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Oracle® Database PL/SQL Packages and Types Reference
11g Release 2 (11.2)

Part Number E16760-04
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21 DBMS_APPLY_ADM

The DBMS_APPLY_ADM package provides subprograms to configure and manage Oracle Streams apply processes, XStream outbound servers, and XStream inbound servers.

This chapter contains the following topics:

See Also:


Using DBMS_APPLY_ADM

This section contains topics which relate to using the DBMS_APPLY_ADM package.


Overview

This package provides interfaces to start, stop, and configure Oracle Streams apply processes, XStream outbound servers, and XStream inbound servers. This package includes subprograms for configuring apply handlers, setting enqueue destinations for messages, and specifying execution directives for messages. This package also provides administrative subprograms that set the instantiation SCN for objects at a destination database. This package also includes subprograms for managing apply errors.

Note:

  • For simplicity, this chapter refers to apply processes, XStream outbound servers, and XStream inbound servers as apply components. This chapter identifies a specific type of apply component when necessary.

  • Using XStream requires purchasing a license for the Oracle GoldenGate product.


Security Model

Security on this package can be controlled in either of the following ways:

If subprograms in the package are run from within a stored procedure, then the user who runs the subprograms must be granted EXECUTE privilege on the package directly. It cannot be granted through a role.

When the DBMS_APPLY_ADM package is used to manage an Oracle Streams configuration, it requires that the user is granted the privileges of an Oracle Streams administrator.

When the DBMS_APPLY_ADM package is used to manage an XStream configuration, it requires that the user is granted the privileges of an XStream administrator.

Note:

The user must be granted additional privileges to perform some administrative tasks using the subprograms in this package, such as setting an apply user. If additional privileges are required for a subprogram, then the privileges are documented in the section that describes the subprogram.

See Also:


Operational Notes

The following sections contain operational notes for this package:

Deprecated Apply Component Parameter Value

Note:

Oracle recommends that you do not use deprecated apply component parameter values. Support for deprecated features is for backward compatibility only.

The NONE value for the commit_serialization apply component parameter is deprecated. It is replaced by the DEPENDENT_TRANSACTIONS value.


Summary of DBMS_APPLY_ADM Subprograms

Table 21-1 DBMS_APPLY_ADM Package Subprograms

Subprogram Description

ADD_STMT_HANDLER Procedure

Adds a statement DML handler for a specified operation on a specified database object to a single apply component or to all apply components in the database

ALTER_APPLY Procedure

Alters an apply component

COMPARE_OLD_VALUES Procedure

Specifies whether to compare the old value of one or more columns in a row logical change record (row LCR) with the current value of the corresponding columns at the destination site during apply

CREATE_APPLY Procedure

Creates an apply component

CREATE_OBJECT_DEPENDENCY Procedure

Creates an object dependency

DELETE_ALL_ERRORS Procedure

Deletes all the error transactions for the specified apply component

DELETE_ERROR Procedure

Deletes the specified error transaction

DROP_APPLY Procedure

Drops an apply component

DROP_OBJECT_DEPENDENCY Procedure

Drops an object dependency

EXECUTE_ALL_ERRORS Procedure

Reexecutes the error transactions for the specified apply component

EXECUTE_ERROR Procedure

Reexecutes the specified error transaction

GET_ERROR_MESSAGE Function

Returns the message payload from the error queue for the specified message number and transaction identifier

REMOVE_STMT_HANDLER

Removes a statement DML handler for a specified operation on a specified database object from a single apply component or from all apply components in the database

SET_CHANGE_HANDLER Procedure

Sets or unsets a statement DML handler that tracks changes for a specified operation on a specified database object for a single apply component

SET_DML_HANDLER Procedure

Sets a user procedure as a procedure DML handler for a specified operation on a specified database object for a single apply component or for all apply components in the database

SET_ENQUEUE_DESTINATION Procedure

Sets the queue where the apply component automatically enqueues a message that satisfies the specified rule

SET_EXECUTE Procedure

Specifies whether a message that satisfies the specified rule is executed by an apply component

SET_GLOBAL_INSTANTIATION_SCN Procedure

Records the specified instantiation SCN for the specified source database and, optionally, for the schemas at the source database and the tables owned by these schemas

SET_KEY_COLUMNS Procedures

Records the set of columns to be used as the substitute primary key for local apply purposes and removes existing substitute primary key columns for the specified object if they exist

SET_PARAMETER Procedure

Sets an apply parameter to the specified value

SET_SCHEMA_INSTANTIATION_SCN Procedure

Records the specified instantiation SCN for the specified schema in the specified source database and, optionally, for the tables owned by the schema at the source database

SET_TABLE_INSTANTIATION_SCN Procedure

Records the specified instantiation SCN for the specified table in the specified source database

SET_UPDATE_CONFLICT_HANDLER Procedure

Adds, updates, or drops an update conflict handler for the specified object

SET_VALUE_DEPENDENCY Procedure

Sets or removes a value dependency

START_APPLY Procedure

Directs the apply component to start applying messages

STOP_APPLY Procedure

Stops the apply component from applying any messages and rolls back any unfinished transactions being applied


Note:

All procedures commit unless specified otherwise. However, the GET_ERROR_MESSAGE function does not commit.

ADD_STMT_HANDLER Procedure

This procedure adds a statement DML handler for a specified operation on a specified database object. The procedure adds the statement DML handler to a single apply component or to all apply components in the database.

This procedure is overloaded. One version of this procedure contains the statement and comment parameters, and the other does not. The statement parameter enables you to create the statement DML handler and add it to one or more processes in one step. Otherwise, create the statement DML handler using the DBMS_STREAMS_HANDLER_ADM package before adding it to one or more processes.

Syntax

DBMS_APPLY_ADM.ADD_STMT_HANDLER(
   object_name     IN  VARCHAR2,
   operation_name  IN  VARCHAR2,
   handler_name    IN  VARCHAR2,
   statement       IN  CLOB,
   apply_name      IN  VARCHAR2  DEFAULT NULL,
   comment         IN  VARCHAR2  DEFAULT NULL);

DBMS_APPLY_ADM.ADD_STMT_HANDLER(
   object_name     IN  VARCHAR2,
   operation_name  IN  VARCHAR2,
   handler_name    IN  VARCHAR2,
   apply_name      IN  VARCHAR2  DEFAULT NULL);

Parameters

Table 21-2 ADD_STMT_HANDLER Procedure Parameters

Parameter Description

object_name

The name of the source object specified as [schema_name.]object_name. For example, hr.employees. If the schema is not specified, then the current user is the default. The specified object does not need to exist when you run this procedure.

If NULL, then the procedure raises an error.

operation_name

The name of the operation, which can be specified as:

  • INSERT

  • UPDATE

  • DELETE

If NULL, then the procedure raises an error.

Note: Statement DML handlers cannot be specified for LOB operations.

handler_name

The name of the statement DML handler.

If the specified statement DML handler exists, then the statement in the statement parameter is added to the existing handler. Ensure that the existing statement DML handler is for the same operation on the same database object as the settings for the operation_name and object_name parameters, respectively. If the existing handler is for a different operation or database object, then an apply error results when the handler is invoked.

If the specified statement DML handler does not exist and a non-NULL statement parameter is specified, then this procedure creates the statement DML handler.

If the specified statement DML handler does not exist and the statement parameter is not specified or is NULL, then this procedure raises an error.

If NULL, then the procedure raises an error.

statement

The text of the SQL statement to add to the statement DML handler.

If NULL, then the procedure raises an error.

apply_name

The name of the apply component that uses the statement DML handler.

If NULL, then the procedure adds the statement DML handler as a general handler to all apply components in the database.

comment

A comment for the statement DML handler.

If NULL, then no comment is recorded for the statement DML handler.


Usage Notes

The following usage notes apply to this procedure:

The ADD_STMT_HANDLER Procedure and XStream Outbound Servers

This procedure has no effect on XStream outbound servers. Outbound servers ignore all apply handlers.

The ADD_STMT_HANDLER Procedure and XStream Inbound Servers

This procedure functions the same way for apply processes and inbound servers.


ALTER_APPLY Procedure

This procedure alters an apply component.

Syntax

DBMS_APPLY_ADM.ALTER_APPLY(
   apply_name                IN  VARCHAR2,
   rule_set_name             IN  VARCHAR2  DEFAULT NULL,
   remove_rule_set           IN  BOOLEAN   DEFAULT FALSE,
   message_handler           IN  VARCHAR2  DEFAULT NULL
   remove_message_handler    IN  BOOLEAN   DEFAULT FALSE,
   ddl_handler               IN  VARCHAR2  DEFAULT NULL,
   remove_ddl_handler        IN  BOOLEAN   DEFAULT FALSE,
   apply_user                IN  VARCHAR2  DEFAULT NULL,
   apply_tag                 IN  RAW       DEFAULT NULL,
   remove_apply_tag          IN  BOOLEAN   DEFAULT FALSE,
   precommit_handler         IN  VARCHAR2  DEFAULT NULL,
   remove_precommit_handler  IN  BOOLEAN   DEFAULT FALSE,
   negative_rule_set_name    IN  VARCHAR2  DEFAULT NULL,
   remove_negative_rule_set  IN  BOOLEAN   DEFAULT FALSE);

Parameters

Table 21-3 ALTER_APPLY Procedure Parameters

Parameter Description

apply_name

The name of the apply component being altered. You must specify the name of an existing apply component. Do not specify an owner.

rule_set_name

The name of the positive rule set for the apply component. The positive rule set contains the rules that instruct the apply component to apply messages.

If you want to use a positive rule set for the apply component, then you must specify an existing rule set in the form [schema_name.]rule_set_name. For example, to specify a positive rule set in the hr schema named job_apply_rules, enter hr.job_apply_rules. If the schema is not specified, then the current user is the default.

An error is returned if the specified rule set does not exist. You can create a rule set and add rules to it using the DBMS_STREAMS_ADM package or the DBMS_RULE_ADM package.

If you specify NULL and the remove_rule_set parameter is set to FALSE, then this procedure retains any existing positive rule set for the specified apply component. If you specify NULL and the remove_rule_set parameter is set to TRUE, then this procedure removes any existing positive rule set from the specified apply component.

remove_rule_set

If TRUE, then the procedure removes the positive rule set for the specified apply component. If you remove the positive rule set for an apply component, and the apply component does not have a negative rule set, then the apply component dequeues all messages in its queue.

If you remove the positive rule set for an apply component, and a negative rule set exists for the apply component, then the apply component dequeues all messages in its queue that are not discarded by the negative rule set.

If FALSE, then the procedure retains the positive rule set for the specified apply component.

If the rule_set_name parameter is non-NULL, then this parameter should be set to FALSE.

message_handler

A user-defined procedure that processes non-LCR messages in the queue for the apply component.

See "Usage Notes" in the CREATE_APPLY Procedure for more information about a message handler procedure.

remove_message_handler

If TRUE, then the procedure removes the message handler for the specified apply component.

If FALSE, then the procedure retains any message handler for the specified apply component.

If the message_handler parameter is non-NULL, then this parameter should be set to FALSE.

ddl_handler

A user-defined procedure that processes DDL logical change records (DDL LCRs) in the queue for the apply component.

All applied DDL LCRs commit automatically. Therefore, if a DDL handler calls the EXECUTE member procedure of a DDL LCR, then a commit is performed automatically.

See "Usage Notes" in the CREATE_APPLY Procedure for more information about a DDL handler procedure.

remove_ddl_handler

If TRUE, then the procedure removes the DDL handler for the specified apply component.

If FALSE, then the procedure retains any DDL handler for the specified apply component.

If the ddl_handler parameter is non-NULL, then this parameter should be set to FALSE.

apply_user

The user in whose security domain an apply component dequeues messages that satisfy its rule sets, applies messages directly to database objects, runs custom rule-based transformations, and runs apply handlers. If NULL, then the apply user is not changed.

If a non-NULL value is specified to change the apply user, then the user who invokes the ALTER_APPLY procedure must be granted the DBA role. Only the SYS user can set the apply_user to SYS.

If you change the apply user, then this procedure grants the new apply user dequeue privilege on the queue used by the apply component. It also configures the user as a secure queue user of the queue.

In addition to the privileges granted by this procedure, you also should grant the following privileges to the apply user:

  • The necessary privileges to perform DML and DDL changes on the apply objects

  • EXECUTE privilege on the rule sets used by the apply component

  • EXECUTE privilege on all rule-based transformation functions used in the rule set

  • EXECUTE privilege on all apply handler procedures

These privileges can be granted directly to the apply user, or they can be granted through roles.

In addition, the apply user must be granted the EXECUTE privilege on all packages, including Oracle-supplied packages, that are invoked in subprograms run by the apply component. These privileges must be granted directly to the apply user. They cannot be granted through roles.

By default, this parameter is set to the user who created the apply component by running either the CREATE_APPLY procedure in this package or a procedure in the DBMS_STREAMS_ADM package.

Note: If the apply user for an apply component is dropped using DROP USER . . . CASCADE, then the apply component is also dropped automatically.

apply_tag

A binary tag that is added to redo entries generated by the specified apply component. The tag is a binary value that can be used to track LCRs.

The tag is relevant only if a capture process at the database where the apply component is running will capture changes made by the apply component. If so, then the captured changes will include the tag specified by this parameter.

If NULL, the default, then the apply tag for the apply component is not changed.

The following is an example of a tag with a hexadecimal value of 17:

HEXTORAW('17')

See Also: Oracle Streams Replication Administrator's Guide for more information about tags

remove_apply_tag

If TRUE, then the procedure sets the apply tag for the specified apply component to NULL, and the apply component generates redo entries with NULL tags.

If FALSE, then the procedure retains any apply tag for the specified apply component.

If the apply_tag parameter is non-NULL, then this parameter should be set to FALSE.

precommit_handler

A user-defined procedure that can receive internal commit directives in the queue for the apply component before they are processed by the apply component. Typically, precommit handlers are used for auditing commit information for transactions processed by an apply component.

An internal commit directive is enqueued in the following ways:

  • When a capture process captures row LCRs, the capture process enqueues the commit directive for the transaction that contains the row LCRs.

  • When a user or application enqueues messages and then issues a COMMIT statement, the commit directive is enqueued automatically.

For a captured row LCR, a commit directive contains the commit SCN of the transaction from the source database. For a user message, the commit SCN is generated by the apply component.

The precommit handler procedure must conform to the following restrictions:

  • Any work that commits must be an autonomous transaction.

  • Any rollback must be to a named savepoint created in the procedure.

If a precommit handler raises an exception, then the entire apply transaction is rolled back, and all of the messages in the transaction are moved to the error queue.

See "Usage Notes" in the CREATE_APPLY Procedure for more information about a precommit handler procedure.

remove_precommit_handler

If TRUE, then the procedure removes the precommit handler for the specified apply component.

If FALSE, then the procedure retains any precommit handler for the specified apply component.

If the precommit_handler parameter is non-NULL, then this parameter should be set to FALSE.

negative_rule_set_name

The name of the negative rule set for the apply component. The negative rule set contains the rules that instruct the apply component to discard messages.

If you want to use a negative rule set for the apply component, then you must specify an existing rule set in the form [schema_name.]rule_set_name. For example, to specify a negative rule set in the hr schema named neg_apply_rules, enter hr.neg_apply_rules. If the schema is not specified, then the current user is the default.

An error is returned if the specified rule set does not exist. You can create a rule set and add rules to it using the DBMS_STREAMS_ADM package or the DBMS_RULE_ADM package.

If you specify NULL and the remove_negative_rule_set parameter is set to FALSE, then the procedure retains any existing negative rule set. If you specify NULL and the remove_negative_rule_set parameter is set to TRUE, then the procedure removes any existing negative rule set.

If you specify both a positive and a negative rule set for an apply component, then the negative rule set is always evaluated first.

remove_negative_rule_set

If TRUE, then the procedure removes the negative rule set for the specified apply component. If you remove the negative rule set for an apply component, and the apply component does not have a positive rule set, then the apply component dequeues all messages in its queue.

If you remove the negative rule set for an apply component, and a positive rule set exists for the apply component, then the apply component dequeues all messages in its queue that are not discarded by the positive rule set.

If FALSE, then the procedure retains the negative rule set for the specified apply component.

If the negative_rule_set_name parameter is non-NULL, then this parameter should be set to FALSE.


Usage Notes

The following usage notes apply to this procedure:

Automatic Restart of Apply Components

An apply component is stopped and restarted automatically when you change the value of one or more of the following ALTER_APPLY procedure parameters:

The ALTER_APPLY Procedure and XStream Outbound Servers

The following usage notes apply to this procedure and XStream outbound servers:

The ALTER_APPLY Procedure and XStream Inbound Servers

Inbound servers can use apply handlers. However, inbound servers only process LCRs. Therefore, inbound servers ignore message handlers specified in the message_handler parameter.


COMPARE_OLD_VALUES Procedure

This procedure specifies whether to compare the old values of one or more columns in a row logical change record (row LCR) with the current values of the corresponding columns at the destination site during apply. This procedure is relevant only for UPDATE and DELETE operations because only these operations result in old column values in row LCRs. The default is to compare old values for all columns.

This procedure is overloaded. The column_list and column_table parameters are mutually exclusive.

See Also:

Oracle Streams Replication Administrator's Guide for more information about conflict detection and resolution in an Oracle Streams environment

Syntax

DBMS_APPLY_ADM.COMPARE_OLD_VALUES(
   object_name         IN VARCHAR2,
   column_list         IN VARCHAR2,
   operation           IN VARCHAR2 DEFAULT 'UPDATE',
   compare             IN BOOLEAN  DEFAULT TRUE,
   apply_database_link IN VARCHAR2 DEFAULT NULL);

DBMS_APPLY_ADM.COMPARE_OLD_VALUES(
   object_name         IN VARCHAR2,
   column_table        IN DBMS_UTILITY.LNAME_ARRAY,
   operation           IN VARCHAR2 DEFAULT 'UPDATE',
   compare             IN BOOLEAN  DEFAULT TRUE,
   apply_database_link IN VARCHAR2 DEFAULT NULL);

Parameters

Table 21-4 COMPARE_OLD_VALUES Procedure Parameters

Parameter Description

object_name

The name of the source table specified as [schema_name.]object_name. For example, hr.employees. If the schema is not specified, then the current user is the default.

column_list

A comma-delimited list of column names in the table. There must be no spaces between entries.

Specify * to include all nonkey columns.

column_table

A PL/SQL index-by table of type DBMS_UTILITY.LNAME_ARRAY that contains names of columns in the table. The first column name should be at position 1, the second at position 2, and so on. The table does not need to be NULL terminated.

operation

The name of the operation, which can be specified as:

  • UPDATE for UPDATE operations

  • DELETE for DELETE operations

  • * for both UPDATE and DELETE operations

compare

If compare is TRUE, the old values of the specified columns are compared during apply.

If compare is FALSE, the old values of the specified columns are not compared during apply.

apply_database_link

The name of the database link to a non-Oracle database. This parameter should be set only when the destination database is a non-Oracle database.


Usage Notes

The following usage notes apply to this procedure:

Conflict Detection

By default, an apply component uses the old column values in a row LCR to detect conflicts. You can choose not to compare old column values to avoid conflict detection for specific tables. For example, if you do not want to compare the old values for a set of columns during apply, then, using the COMPARE_OLD_VALUES procedure, specify the set of columns in the column_list or column_table parameter, and set the compare parameter to FALSE.

In addition, when the compare_key_only apply component parameter is set to Y, automatic conflict detection is disabled, and the apply component only uses key columns to identify the table row for a row LCR. Key columns include primary key, unique key, and foreign key columns. When the compare_key_only apply component parameter is set to N, automatic conflict detection is enabled, and the apply component uses all of the old values in a row LCR to identify the table row for a row LCR.

Note:

  • An apply component compares old values for non-key columns when they are present in a row LCR and when the apply component parameter compare_key_only is set to N.

  • This procedure raises an error if a key column is specified in column_list or column_table and the compare parameter is set to FALSE.

See Also:

SET_PARAMETER Procedure for more information about the compare_key_columns apply component parameter

The COMPARE_OLD_VALUES Procedure and XStream Outbound Servers

This procedure has no effect on XStream outbound servers.

The COMPARE_OLD_VALUES Procedure and XStream Inbound Servers

This procedure functions the same way for apply processes and inbound servers.


CREATE_APPLY Procedure

This procedure creates an apply component.

Syntax

DBMS_APPLY_ADM.CREATE_APPLY(
     queue_name              IN  VARCHAR2,
     apply_name              IN  VARCHAR2,
     rule_set_name           IN  VARCHAR2  DEFAULT NULL,
     message_handler         IN  VARCHAR2  DEFAULT NULL,
     ddl_handler             IN  VARCHAR2  DEFAULT NULL,
     apply_user              IN  VARCHAR2  DEFAULT NULL,
     apply_database_link     IN  VARCHAR2  DEFAULT NULL,
     apply_tag               IN  RAW       DEFAULT '00',
     apply_captured          IN  BOOLEAN   DEFAULT FALSE,
     precommit_handler       IN  VARCHAR2  DEFAULT NULL,
     negative_rule_set_name  IN  VARCHAR2  DEFAULT NULL,
     source_database         IN  VARCHAR2  DEFAULT NULL);

Parameters

Table 21-5 CREATE_APPLY Procedure Parameters

Parameter Description

queue_name

The name of the queue from which the apply component dequeues messages. You must specify an existing queue in the form [schema_name.]queue_name. For example, to specify a queue in the hr schema named streams_queue, enter hr.streams_queue. If the schema is not specified, then the current user is the default.

Note: The queue_name setting cannot be altered after the apply component is created.

apply_name

The name of the apply component being created. A NULL specification is not allowed. Do not specify an owner.

The specified name must not match the name of an existing apply component or messaging client.

Note: The apply_name setting cannot be altered after the apply component is created.

rule_set_name

The name of the positive rule set for the apply component. The positive rule set contains the rules that instruct the apply component to apply messages.

If you want to use a positive rule set for the apply component, then you must specify an existing rule set in the form [schema_name.]rule_set_name. For example, to specify a positive rule set in the hr schema named job_apply_rules, enter hr.job_apply_rules. If the schema is not specified, then the current user is the default.

If you specify NULL, and no negative rule set is specified, then the apply component applies either all captured messages or all messages in the persistent queue, depending on the setting of the apply_captured parameter.

An error is returned if the specified rule set does not exist. You can create a rule set and add rules to it using the DBMS_STREAMS_ADM package or the DBMS_RULE_ADM package.

message_handler

A user-defined procedure that processes non-LCR messages in the queue for the apply component.

See "Usage Notes" for more information about a message handler procedure.

ddl_handler

A user-defined procedure that processes DDL logical change record (DDL LCRs) in the queue for the apply component.

All applied DDL LCRs commit automatically. Therefore, if a DDL handler calls the EXECUTE member procedure of a DDL LCR, then a commit is performed automatically.

See "Usage Notes" for more information about a DDL handler procedure.

apply_user

The user who applies all DML and DDL changes that satisfy the apply component rule sets and who runs user-defined apply handlers. If NULL, then the user who runs the CREATE_APPLY procedure is used.

The apply user is the user in whose security domain an apply component dequeues messages that satisfy its rule sets, applies messages directly to database objects, runs custom rule-based transformations configured for apply component rules, and runs apply handlers configured for the apply component. This user must have the necessary privileges to apply changes. This procedure grants the apply user dequeue privilege on the queue used by the apply component and configures the user as a secure queue user of the queue.

In addition to the privileges granted by this procedure, you also should grant the following privileges to the apply user:

  • The necessary privileges to perform DML and DDL changes on the apply objects

  • EXECUTE privilege on the rule sets used by the apply component

  • EXECUTE privilege on all rule-based transformation functions used in the rule set

  • EXECUTE privilege on all apply handler procedures

These privileges can be granted directly to the apply user, or they can be granted through roles.

In addition, the apply user must be granted EXECUTE privilege on all packages, including Oracle-supplied packages, that are invoked in subprograms run by the apply component. These privileges must be granted directly to the apply user. They cannot be granted through roles.

Note: If the apply user for an apply component is dropped using DROP USER . . . CASCADE, then the apply component is also dropped automatically.

See "Usage Notes" for more information about this parameter.

apply_database_link

The database at which the apply component applies messages. This parameter is used by an apply component when applying changes from Oracle to non-Oracle systems, such as Sybase. Set this parameter to NULL to specify that the apply component applies messages at the local database.

Note: The apply_database_link setting cannot be altered after the apply component is created.

apply_tag

A binary tag that is added to redo entries generated by the specified apply component. The tag is a binary value that can be used to track LCRs.

The tag is relevant only if a capture process at the database where the apply component is running will capture changes made by the apply component. If so, then the captured changes will include the tag specified by this parameter.

By default, the tag for an apply component is the hexadecimal equivalent of '00' (double zero).

The following is an example of a tag with a hexadecimal value of 17:

HEXTORAW('17')

If NULL, then the apply component generates redo entries with NULL tags.

See Also: Oracle Streams Replication Administrator's Guide for more information about tags

apply_captured

Either TRUE or FALSE.

If TRUE, then the apply component applies only the captured LCRs in the queue. Captured LCRs are LCRs that were captured by an Oracle Streams capture process.

If FALSE, then the apply component applies only the messages in a persistent queue. These are messages that were not captured by an Oracle Streams capture process, such as persistent LCRs or user messages.

To apply both captured LCRs and messages in a persistent queue, you must create at least two apply components.

Note: The apply_captured setting cannot be altered after the apply component is created.

See Also: Oracle Streams Concepts and Administration for more information about processing messages with an apply component

precommit_handler

A user-defined procedure that can receive internal commit directives in the queue for the apply component before they are processed by the apply component. Typically, precommit handlers are used for auditing commit information for transactions processed by an apply component.

An internal commit directive is enqueued in the following ways:

  • When a capture process captures row LCRs, the capture process enqueues the commit directive for the transaction that contains the row LCRs.

  • When a synchronous capture captures row LCRs, the the persistent LCRs that were enqueued by the synchronous capture are organized into a message group. The synchronous capture records the transaction identifier in each persistent LCR in a transaction.

  • When a user or application enqueues messages and then issues a COMMIT statement, the commit directive is enqueued automatically.

For a row LCR captured by a capture process or synchronous capture, a commit directive contains the commit SCN of the transaction from the source database. For a message enqueued by a user or application, the commit SCN is generated by the apply component.

The precommit handler procedure must conform to the following restrictions:

  • Any work that commits must be an autonomous transaction.

  • Any rollback must be to a named savepoint created in the procedure.

If a precommit handler raises an exception, then the entire apply transaction is rolled back, and all of the messages in the transaction are moved to the error queue.

See "Usage Notes" for more information about a precommit handler procedure.

negative_rule_set_name

The name of the negative rule set for the apply component. The negative rule set contains the rules that instruct the apply component to discard messages.

If you want to use a negative rule set for the apply component, then you must specify an existing rule set in the form [schema_name.]rule_set_name. For example, to specify a negative rule set in the hr schema named neg_apply_rules, enter hr.neg_apply_rules. If the schema is not specified, then the current user is the default.

If you specify NULL, and no positive rule set is specified, then the apply component applies either all captured LCRs or all of the messages in the persistent queue, depending on the setting of the apply_captured parameter.

An error is returned if the specified rule set does not exist. You can create a rule set and add rules to it using the DBMS_STREAMS_ADM package or the DBMS_RULE_ADM package.

If you specify both a positive and a negative rule set for an apply component, then the negative rule set is always evaluated first.

source_database

The global name of the source database for the changes that will be applied by the apply component. The source database is the database where the changes originated. If an apply component applies captured messages, then the apply component can apply messages from only one capture process at one source database.

If NULL, then the source database name of the first LCR received by the apply component is used for the source database.

If you do not include the domain name, then the procedure appends it to the database name automatically. For example, if you specify DBS1 and the domain is NET, then the procedure specifies DBS1.NET automatically.

The rules in the apply component rule sets determine which messages are dequeued by the apply component. If the apply component dequeues an LCR with a source database that is different than the source database for the apply component, then an error is raised. You can determine the source database for an apply component by querying the DBA_APPLY_PROGRESS data dictionary view.


Usage Notes

The following sections describe usage notes for this procedure:

DBA Role Requirement

If the user who invokes this procedure is different from the user specified in the apply_user parameter, then the invoking user must be granted the DBA role. If the user who invokes this procedure is the same as the user specified in the apply_user parameter, then the DBA role is not required for the invoking user. Only the SYS user can set the apply_user to SYS.

Handler Procedure Names

For the message_handler, ddl_handler, and precommit_handler parameters, specify an existing procedure in one of the following forms:

If the procedure is in a package, then the package_name must be specified. For example, to specify a procedure in the apply_pkg package in the hr schema named process_ddls, enter hr.apply_pkg.process_ddls. An error is returned if the specified procedure does not exist.

The user who invokes the CREATE_APPLY procedure must have EXECUTE privilege on a specified handler procedure. Also, if the schema_name is not specified, then the user who invokes the CREATE_APPLY procedure is the default.

Message Handler and DDL Handler Procedure

The procedure specified in both the message_handler parameter and the ddl_handler parameter must have the following signature:

PROCEDURE handler_procedure (
   parameter_name  IN  ANYDATA);

Here, handler_procedure stands for the name of the procedure and parameter_name stands for the name of the parameter passed to the procedure. For the message handler, the parameter passed to the procedure is a ANYDATA encapsulation of a user message. For the DDL handler procedure, the parameter passed to the procedure is a ANYDATA encapsulation of a DDL LCR.

See Also:

Chapter 247, "Logical Change Record TYPEs" for information about DDL LCRs

Precommit Handler Procedure

The procedure specified in the precommit_handler parameter must have the following signature:

PROCEDURE handler_procedure (
   parameter_name   IN  NUMBER);

Here, handler_procedure stands for the name of the procedure and parameter_name stands for the name of the parameter passed to the procedure. The parameter passed to the procedure is the commit SCN of a commit directive.

The CREATE_APPLY Procedure and XStream Outbound Servers

This procedure cannot create an XStream outbound servers. To create an XStream outbound server, use the DBMS_XSTREAM_ADM package.

The CREATE_APPLY Procedure and XStream Inbound Servers

The following usage notes apply to this procedure and XStream inbound servers:


CREATE_OBJECT_DEPENDENCY Procedure

This procedure creates an object dependency. An object dependency is a virtual dependency definition that defines a parent-child relationship between two objects at a destination database.

An apply component schedules execution of transactions that involve the child object after all transactions with a lower commit system change number (commit SCN) that involve the parent object have been committed. An apply component uses the object identifier of the objects in the logical change records (LCRs) to detect dependencies. The apply component does not use column values in the LCRs to detect dependencies.

Note:

An error is raised if NULL is specified for either of the procedure parameters.

Syntax

DBMS_APPLY_ADM.CREATE_OBJECT_DEPENDENCY(
   object_name         IN  VARCHAR2,
   parent_object_name  IN  VARCHAR2);

Parameters

Table 21-6 CREATE_OBJECT_DEPENDENCY Procedure Parameters

Parameter Description

object_name

The name of the child database object, specified as [schema_name.]object_name. For example, hr.employees. If the schema is not specified, then the current user is the default.

parent_object_name

The name of the parent database object, specified as [schema_name.]object_name. For example, hr.departments. If the schema is not specified, then the current user is the default.


Usage Notes

The following usage notes apply to this procedure:

The CREATE_OBJECT_DEPENDENCY Procedure and XStream Outbound Servers

This procedure has no effect on XStream outbound servers.

The CREATE_OBJECT_DEPENDENCY Procedure and XStream Inbound Servers

This procedure functions the same way for apply processes and inbound servers.


DELETE_ALL_ERRORS Procedure

This procedure deletes all the error transactions for the specified apply component.

Syntax

DBMS_APPLY_ADM.DELETE_ALL_ERRORS(
   apply_name  IN  VARCHAR2 DEFAULT NULL);

Parameter

Table 21-7 DELETE_ALL_ERRORS Procedure Parameter

Parameter Description

apply_name

The name of the apply component that raised the errors while processing the transactions. Do not specify an owner.

If NULL, then all error transactions for all apply components are deleted.


Usage Notes

The following usage notes apply to this procedure:

The DELETE_ALL_ERRORS Procedure and XStream Outbound Servers

Outbound servers do not enqueue error transactions into an error queue. This procedure has no effect on XStream outbound servers.

The DELETE_ALL_ERRORS Procedure and XStream Inbound Servers

This procedure functions the same way for apply processes and inbound servers.


DELETE_ERROR Procedure

This procedure deletes the specified error transaction.

Syntax

DBMS_APPLY_ADM.DELETE_ERROR(
   local_transaction_id  IN  VARCHAR2);

Parameter

Table 21-8 DELETE_ERROR Procedure Parameter

Parameter Description

local_transaction_id

The identification number of the error transaction to delete. If the specified transaction does not exist in the error queue, then an error is raised.


Usage Notes

The following usage notes apply to this procedure:

The DELETE_ERROR Procedure and XStream Outbound Servers

Outbound servers do not enqueue error transactions into an error queue. This procedure has no effect on XStream outbound servers.

The DELETE_ERROR Procedure and XStream Inbound Servers

This procedure functions the same way for apply processes and inbound servers.


DROP_APPLY Procedure

This procedure drops an apply component.

Syntax

DBMS_APPLY_ADM.DROP_APPLY(
     apply_name             IN  VARCHAR2,
     drop_unused_rule_sets  IN  BOOLEAN  DEFAULT FALSE);

Parameters

Table 21-9 DROP_APPLY Procedure Parameters

Parameter Description

apply_name

The name of the apply component being dropped. You must specify an existing apply component name. Do not specify an owner.

drop_unused_rule_sets

If TRUE, then the procedure drops any rule sets, positive and negative, used by the specified apply component if these rule sets are not used by any other Oracle Streams or XStream component. These components include capture processes, propagations, apply processes, inbound servers, and messaging clients. If this procedure drops a rule set, then this procedure also drops any rules in the rule set that are not in another rule set.

If FALSE, then the procedure does not drop the rule sets used by the specified apply component, and the rule sets retain their rules.


Usage Notes

The following usage notes apply to this procedure:

The DROP_APPLY Procedure and Rules

When you use this procedure to drop an apply component, information about rules created for the apply component using the DBMS_STREAMS_ADM package is removed from the data dictionary views for rules. Information about such a rule is removed even if the rule is not in either the positive or negative rule set for the apply component. The following are the data dictionary views for rules:

The DROP_APPLY Procedure and XStream Outbound Servers

When the DROP_APPLY procedure is executed on an outbound server, it runs the DROP_OUTBOUND procedure in the DBMS_XSTREAM_ADM package. Therefore, it might also drop the outbound server's capture process and queue.

The DROP_APPLY Procedure and XStream Inbound Servers

When the DROP_APPLY procedure is executed on an inbound server, it runs the DROP_INBOUND procedure in the DBMS_XSTREAM_ADM package. Therefore, it might also drop the inbound server's queue.


DROP_OBJECT_DEPENDENCY Procedure

This procedure drops an object dependency. An object dependency is a virtual dependency definition that defines a parent-child relationship between two objects at a destination database.

Note:

  • An error is raised if an object dependency does not exist for the specified database objects.

  • An error is raised if NULL is specified for either of the procedure parameters.

Syntax

DBMS_APPLY_ADM.DROP_OBJECT_DEPENDENCY(
     object_name         IN  VARCHAR2,
     parent_object_name  IN  VARCHAR2);

Parameters

Table 21-10 DROP_OBJECT_DEPENDENCY Procedure Parameters

Parameter Description

object_name

The name of the child database object, specified as [schema_name.]object_name. For example, hr.employees. If the schema is not specified, then the current user is the default.

parent_object_name

The name of the parent database object, specified as [schema_name.]object_name. For example, hr.departments. If the schema is not specified, then the current user is the default.


Usage Notes

The following usage notes apply to this procedure:

The DROP_OBJECT_DEPENDENCY Procedure and XStream Outbound Servers

This procedure has no effect on XStream outbound servers.

The DROP_OBJECT_DEPENDENCY Procedure and XStream Inbound Servers

This procedure functions the same way for apply processes and inbound servers.


EXECUTE_ALL_ERRORS Procedure

This procedure reexecutes the error transactions in the error queue for the specified apply component.

The transactions are reexecuted in commit SCN order. Error reexecution stops if an error is raised.

See Also:

Oracle Streams Concepts and Administration for more information about the error queue

Syntax

DBMS_APPLY_ADM.EXECUTE_ALL_ERRORS(
   apply_name       IN  VARCHAR2  DEFAULT NULL,
   execute_as_user  IN  BOOLEAN   DEFAULT FALSE);

Parameters

Table 21-11 EXECUTE_ALL_ERRORS Procedure Parameters

Parameter Description

apply_name

The name of the apply component that raised the errors while processing the transactions. Do not specify an owner.

If NULL, then all error transactions for all apply components are reexecuted.

execute_as_user

If TRUE, then the procedure reexecutes the transactions in the security context of the current user.

If FALSE, then the procedure reexecutes each transaction in the security context of the original receiver of the transaction. The original receiver is the user who was processing the transaction when the error was raised. The DBA_APPLY_ERROR data dictionary view lists the original receiver for each error transaction.

The user who executes the transactions must have privileges to perform DML and DDL changes on the apply objects and to run any apply handlers. This user must also have dequeue privileges on the queue used by the apply component.


Usage Notes

The following usage notes apply to this procedure:

The EXECUTE_ALL_ERRORS Procedure and XStream Outbound Servers

Outbound servers do not enqueue error transactions into an error queue. This procedure cannot be used with XStream outbound servers.

The EXECUTE_ALL_ERRORS Procedure and XStream Inbound Servers

This procedure functions the same way for apply processes and inbound servers.


EXECUTE_ERROR Procedure

This procedure reexecutes the specified error transaction in the error queue.

See Also:

Oracle Streams Concepts and Administration for more information about the error queue

Syntax

DBMS_APPLY_ADM.EXECUTE_ERROR(
   local_transaction_id  IN  VARCHAR2,
   execute_as_user       IN  BOOLEAN   DEFAULT FALSE,
   user_procedure        IN  VARCHAR2  DEFAULT NULL);

Parameters

Table 21-12 EXECUTE_ERROR Procedure Parameters

Parameter Description

local_transaction_id

The identification number of the error transaction to execute. If the specified transaction does not exist in the error queue, then an error is raised.

execute_as_user

If TRUE, then the procedure reexecutes the transaction in the security context of the current user.

If FALSE, then the procedure reexecutes the transaction in the security context of the original receiver of the transaction. The original receiver is the user who was processing the transaction when the error was raised. The DBA_APPLY_ERROR data dictionary view lists the original receiver for each error transaction.

The user who executes the transaction must have privileges to perform DML and DDL changes on the apply objects and to run any apply handlers. This user must also have dequeue privileges on the queue used by the apply component.

user_procedure

A user-defined procedure that modifies the error transaction so that it can be successfully executed.

Specify NULL to execute the error transaction without running a user procedure.

See Also: "Usage Notes" for more information about the user procedure


Usage Notes

The following usage notes apply to this procedure:

The User Procedure

You must specify the full procedure name for the user_procedure parameter in one of the following forms:

If the procedure is in a package, then the package_name must be specified. The user who invokes the EXECUTE_ERROR procedure must have EXECUTE privilege on the specified procedure. Also, if the schema_name is not specified, then the user who invokes the EXECUTE_ERROR procedure is the default.

For example, suppose the procedure_name has the following properties:

In this case, specify the following:

strmadmin.fix_errors.fix_hr_errors

The procedure you create for error handling must have the following signature:

PROCEDURE user_procedure (
     in_anydata                    IN      ANYDATA,
     error_record                  IN      DBA_APPLY_ERROR%ROWTYPE,
     error_message_number          IN      NUMBER,
     messaging_default_processing  IN OUT  BOOLEAN,
     out_anydata                   OUT     ANYDATA);

The user procedure has the following parameters:

If an LCR is executed using the EXECUTE LCR member procedure in the user procedure, then the LCR is executed directly, and the messaging_default_processing parameter should be set to FALSE. In this case, the LCR is not passed to any apply handlers.

Processing an error transaction with a user procedure results in one of the following outcomes:

The following restrictions apply to the user procedure:

Note:

LCRs containing transactional directives, such as COMMIT and ROLLBACK, are not passed to the user procedure.

The EXECUTE_ERROR Procedure and XStream Outbound Servers

Outbound servers do not enqueue error transactions into an error queue. This procedure cannot be used with XStream outbound servers.

The EXECUTE_ERROR Procedure and XStream Inbound Servers

This procedure functions the same way for apply processes and inbound servers.


GET_ERROR_MESSAGE Function

This function returns the message payload from the error queue for the specified message number and transaction identifier. The message can be a logical change record (LCR) or a non-LCR message.

This function is overloaded. One version of this function contains two OUT parameters. These OUT parameters contain the destination queue into which the message should be enqueued, if one exists, and whether or not the message should be executed. The destination queue is specified using the SET_ENQUEUE_DESTINATION procedure, and the execution directive is specified using the SET_EXECUTE procedure.

Syntax

DBMS_APPLY_ADM.GET_ERROR_MESSAGE(
   message_number          IN   NUMBER, 
   local_transaction_id    IN   VARCHAR2,
   destination_queue_name  OUT  VARCHAR2, 
   execute                 OUT  BOOLEAN)
RETURN ANYDATA;

DBMS_APPLY_ADM.GET_ERROR_MESSAGE(
   message_number          IN   NUMBER, 
   local_transaction_id    IN   VARCHAR2)
RETURN ANYDATA;

Parameters

Table 21-13 GET_ERROR_MESSAGE Function Parameters

Parameter Description

message_number

The identification number of the message. This number identifies the position of the message in the transaction. Query the DBA_APPLY_ERROR data dictionary view to view the message number of each apply error.

local_transaction_id

Identifier of the error transaction for which to return a message

destination_queue_name

Contains the name of the queue into which the message should be enqueued. If the message should not be enqueued into a queue, then this parameter contains NULL.

execute

Contains TRUE if the message should be executed

Contains FALSE if the message should not be executed


Usage Notes

The following usage notes apply to this procedure:

The GET_ERROR_MESSAGE Procedure and XStream Outbound Servers

Outbound servers do not enqueue error transactions into an error queue. This procedure cannot be used with XStream outbound servers.

The GET_ERROR_MESSAGE Procedure and XStream Inbound Servers

This procedure functions the same way for apply processes and inbound servers.


REMOVE_STMT_HANDLER

This procedure removes a statement DML handler for a specified operation on a specified database object from a single apply component or from all apply components in the database.

Syntax

DBMS_APPLY_ADM.REMOVE_STMT_HANDLER(
   object_name     IN  VARCHAR2,
   operation_name  IN  VARCHAR2,
   handler_name    IN  VARCHAR2,
   apply_name      IN  VARCHAR2  DEFAULT NULL);

Parameters

Table 21-14 REMOVE_STMT_HANDLER Procedure Parameters

Parameter Description

object_name

The name of the source object specified as [schema_name.]object_name. For example, hr.employees. If the schema is not specified, then the current user is the default. The specified object does not need to exist when you run this procedure.

If NULL, then the procedure raises an error.

operation_name

The name of the operation, which can be specified as:

  • INSERT

  • UPDATE

  • DELETE

If NULL, then the procedure raises an error.

handler_name

The name of the statement DML handler.

If NULL, then the procedure raises an error.

apply_name

The name of the apply component that uses the statement DML handler.

If NULL, then the procedure removes the statement DML handler from all apply components in the database.


Usage Notes

The following usage notes apply to this procedure:

The REMOVE_STMT_HANDLER Procedure and XStream Outbound Servers

Outbound servers ignore all apply handlers. This procedure has no effect on XStream outbound servers.

The REMOVE_STMT_HANDLER Procedure and XStream Inbound Servers

This procedure functions the same way for apply processes and inbound servers.


SET_CHANGE_HANDLER Procedure

This procedure sets or unsets a change handler that tracks changes for a specified operation on a specified database object for a single apply component.

A change handler is a special type of statement DML handler that tracks table changes and was created by either the DBMS_STREAMS_ADM.MAINTAIN_CHANGE_TABLE procedure or this SET_CHANGE_HANDLER procedure. Information about change handlers is stored in the ALL_APPLY_CHANGE_HANDLERS and DBA_APPLY_CHANGE_HANDLERS views.

This procedure automatically generates the statement that is added to the change handler based on values specified in the procedure parameters. You should only run this procedure when a configuration that tracks database changes already exists.

Note:

Use the MAINTAIN_CHANGE_TABLE Procedure to configure an environment that tracks table changes

Syntax

DBMS_APPLY_ADM.SET_CHANGE_HANDLER(
   change_table_name    IN  VARCHAR2,
   source_table_name    IN  VARCHAR2,
   capture_values       IN  VARCHAR2,
   apply_name           IN  VARCHAR2,
   operation_name       IN  VARCHAR2,
   change_handler_name  IN  VARCHAR2  DEFAULT NULL);

Parameters

Table 21-15 SET_CHANGE_HANDLER Procedure Parameters

Parameter Description

change_table_name

The table that records changes to the source table.

Specify the table as [schema_name.]table_name. For example, hr.jobs_change_table. If the schema is not specified, then the current user is the default.

If NULL, then the procedure raises an error.

source_table_name

The table at the source database for which changes are recorded.

Specify the table as [schema_name.]table_name. For example, hr.jobs. If the schema is not specified, then the current user is the default.

If NULL, then the procedure raises an error.

capture_values

Specify which values to record in the change table when update operations are performed on the source table:

  • old - To record the original values for an updated column in the source table

  • new - To record the new values for an updated column in the source table

  • * - To record both the original and the new values for an updated column in the source table

If NULL, then the procedure raises an error.

Note: For insert operations, only new column values are captured. For delete operations, only old column values are captured.

apply_name

The name of the apply component that applies changes to the change table. Do not specify an owner.

If NULL, then the procedure raises an error.

operation_name

The name of the operation, which can be specified as:

  • INSERT

  • UPDATE

  • DELETE

If NULL, then the procedure raises an error.

Note: Change handlers cannot be specified for LOB operations.

change_handler_name

The name of the change handler.

If the specified change handler exists, then a statement is added to the existing handler. Ensure that the existing change handler is for the same operation on the same table as the settings for the operation_name and source_table_name parameters, respectively. If the existing handler is for a different operation or table, then an apply error results when the handler is invoked.

If non-NULL and the specified change handler does not exist, then this procedure creates the change handler.

If NULL and a change handler exists for the same operation on the same table as the settings for the operation_name and source_table_name parameters, respectively, then the existing change handler is removed.

If NULL and the specified change handler does not exist, then the procedure raises an error.

See Also: "Usage Notes" for more information about this parameter.


Usage Notes

The following usage notes apply to this procedure:

Checking for an Existing Change Handler

To check for an existing change handler for a specific operation on a specific source table, run the following query:

SELECT HANDLER_NAME, APPLY_NAME FROM DBA_APPLY_CHANGE_HANDLERS
  WHERE  operation_name     = 'operation'
    AND  source_table_owner = 'source_table_owner'
    AND  source_table_name  = 'source_table_name'
    AND  change_table_owner = 'change_table_owner'
    AND  change_table_name  = 'change_table_name';

where:

The SET_CHANGE_HANDLER Procedure and XStream Outbound Servers

Outbound servers ignore all apply handlers. This procedure has no effect on XStream outbound servers.

The SET_CHANGE_HANDLER Procedure and XStream Inbound Servers

This procedure functions the same way for apply processes and inbound servers.


SET_DML_HANDLER Procedure

This procedure sets or unsets a user procedure as a procedure DML handler for a specified operation on a specified database object for a single apply component or for all apply components in the database. The user procedure alters the apply behavior for the specified operation on the specified object.

Syntax

DBMS_APPLY_ADM.SET_DML_HANDLER(
   object_name          IN  VARCHAR2,
   object_type          IN  VARCHAR2,
   operation_name       IN  VARCHAR2,
   error_handler        IN  BOOLEAN   DEFAULT FALSE,
   user_procedure       IN  VARCHAR2,
   apply_database_link  IN  VARCHAR2  DEFAULT NULL,
   apply_name           IN  VARCHAR2  DEFAULT NULL,
   assemble_lobs        IN  BOOLEAN   DEFAULT TRUE);

Parameters

Table 21-16 SET_DML_HANDLER Procedure Parameters

Parameter Description

object_name

The name of the source object specified as [schema_name.]object_name. For example, hr.employees. If the schema is not specified, then the current user is the default. The specified object does not need to exist when you run this procedure.

object_type

The type of the source object. Currently, TABLE is the only possible source object type.

operation_name

The name of the operation, which can be specified as:

  • INSERT

  • UPDATE

  • DELETE

  • LOB_UPDATE

  • DEFAULT

For example, suppose you run this procedure twice for the hr.employees table. In one call, you set operation_name to UPDATE and user_procedure to employees_update. In another call, you set operation_name to INSERT and user_procedure to employees_insert. Both times, you set error_handler to FALSE. In this case, the employees_update procedure is run for UPDATE operations on the hr.employees table, and the employees_insert procedure is run for INSERT operations on the hr.employees table.

Specify DEFAULT to set the procedure as the default procedure DML handler for the database object. In this case, the procedure DML handler is used for any INSERT, UPDATE, DELETE, and LOB_WRITE on the database object, if another procedure DML handler is not specifically set for the operation on the database object.

error_handler

If TRUE, then the specified user procedure is run when a row logical change record (row LCR) involving the specified operation on the specified object raises an apply error. You can code the user procedure to resolve possible error conditions, notify administrators of the error, log the error, or any combination of these actions.

If FALSE, then the handler being set is run for all row LCRs involving the specified operation on the specified object.

user_procedure

A user-defined procedure that is invoked during apply for the specified operation on the specified object. If the procedure is a procedure DML handler, then it is invoked instead of the default apply performed by Oracle. If the procedure is an error handler, then it is invoked when an apply error is encountered.

Specify NULL to unset a procedure DML handler that is set for the specified operation on the specified object.

apply_database_link

The name of the database link to a non-Oracle database. This parameter should be set only when the destination database is a non-Oracle database.

apply_name

The name of the apply component that uses the procedure DML handler or error handler.

If NULL, then the procedure sets the procedure DML handler or error handler as a general handler for all apply components in the database.

If the user_procedure parameter is set to NULL to unset a handler, and the handler being unset is set for a specific apply component, then use the apply_name parameter to specify the apply component to unset the handler.

assemble_lobs

If TRUE, then LOB assembly is used for LOB columns in LCRs processed by the handler. LOB assembly combines multiple LCRs for a LOB column resulting from a single row change into one row LCR before passing the LCR to the handler. Database compatibility must be 10.2.0 or higher to use LOB assembly.

If FALSE, then LOB assembly is not used for LOB columns in LCRs processed by the handler.


Usage Notes

The following usage notes apply to this procedure:

Run the SET_DML_HANDLER Procedure at the Destination Database

Run this procedure at the destination database. The SET_DML_HANDLER procedure provides a way for users to apply logical change records containing DML changes (row LCRs) using a customized apply.

Procedure DML Handlers and Error Handlers

If the error_handler parameter is set to TRUE, then it specifies that the user procedure is an error handler. An error handler is invoked only when a row LCR raises an apply error. Such an error can result from a data conflict if no conflict handler is specified or if the update conflict handler cannot resolve the conflict. If the error_handler parameter is set to FALSE, then the user procedure is a procedure DML handler, not an error handler, and a procedure DML handler is always run instead of performing the specified operation on the specified object.

This procedure either sets a procedure DML handler or an error handler for a particular operation on an object. It cannot set both a procedure DML handler and an error handler for the same object and operation.

Note:

Currently, setting an error handler for an apply component that is applying changes to a non-Oracle database is not supported.

The apply_name Parameter

If the apply_name parameter is non-NULL, then the procedure DML handler or error handler is set for the specified apply component. In this case, this handler is not invoked for other apply components at the local destination database. If the apply_name parameter is NULL, the default, then the handler is set as a general handler for all apply components at the destination database. When a handler is set for a specific apply component, then this handler takes precedence over any general handlers. For example, consider the following scenario:

In this case, the apply_hr apply component uses the handler_hr procedure DML handler for UPDATE operations on the hr.employees table.

At the source database, you must specify an unconditional supplemental log group for the columns needed by a DML or error handler.

Signature of a DML Handler Procedure or Error Handler Procedure

The SET_DML_HANDLER procedure can be used to set either a procedure DML handler or an error handler for row LCRs that perform a specified operation on a specified object. The signatures of a DML handler procedure and of an error handler procedure are described following this section.

In either case, you must specify the full procedure name for the user_procedure parameter in one of the following forms:

If the procedure is in a package, then the package_name must be specified. The user who invokes the SET_DML_HANDLER procedure must have EXECUTE privilege on the specified procedure. Also, if the schema_name is not specified, then the user who invokes the SET_DML_HANDLER procedure is the default.

For example, suppose the procedure_name has the following properties:

In this case, specify the following:

hr.apply_pkg.employees_default

The following restrictions apply to the user procedure:

See Also:

Oracle Streams Replication Administrator's Guide for information about and restrictions regarding procedure DML handlers and LOB, LONG, and LONG RAW data types

The procedure specified in the user_procedure parameter must have the following signature:

PROCEDURE user_procedure (
   parameter_name  IN  ANYDATA);

Here, user_procedure stands for the name of the procedure and parameter_name stands for the name of the parameter passed to the procedure. The parameter passed to the procedure is a ANYDATA encapsulation of a row LCR.

See Also:

Chapter 247, "Logical Change Record TYPEs" for more information about LCRs

The procedure you create for error handling must have the following signature:

PROCEDURE user_procedure (
     message            IN  ANYDATA,
     error_stack_depth  IN  NUMBER,
     error_numbers      IN  DBMS_UTILITY.NUMBER_ARRAY,
     error_messages     IN  emsg_array);

If you want to retry the DML operation within the error handler, then have the error handler procedure run the EXECUTE member procedure for the LCR. The last error raised is on top of the error stack. To specify the error message at the top of the error stack, use error_numbers(1) and error_messages(1).

Note:

  • Each parameter is required and must have the specified data type. However, you can change the names of the parameters.

  • The emsg_array value must be a user-defined array that is a table of type VARCHAR2 with at least 76 characters.

Running an error handler results in one of the following outcomes:

LOB Assembly

Do not modify LONG, LONG RAW, or nonassembled LOB column data in an LCR with procedure DML handlers, error handlers, or custom rule-based transformation functions. Procedure DML handlers and error handlers can modify LOB columns in row LCRs that have been constructed by LOB assembly.

The SET_DML_HANDLER Procedure and XStream Outbound Servers

Outbound servers ignore all apply handlers. This procedure has no effect on XStream outbound servers.

The SET_DML_HANDLER Procedure and XStream Inbound Servers

This procedure functions the same way for apply processes and inbound servers.


SET_ENQUEUE_DESTINATION Procedure

This procedure sets the queue where the apply component automatically enqueues a message that satisfies the specified rule.

This procedure modifies the specified rule's action context to specify the queue. A rule action context is optional information associated with a rule that is interpreted by the client of the rules engine after the rule evaluates to TRUE for a message. In this case, the client of the rules engine is an apply component. The information in an action context is an object of type SYS.RE$NV_LIST, which consists of a list of name-value pairs.

A queue destination specified by this procedure always consists of the following name-value pair in an action context:

Syntax

DBMS_APPLY_ADM.SET_ENQUEUE_DESTINATION(
  rule_name               IN  VARCHAR2,
  destination_queue_name  IN  VARCHAR2);

Parameters

Table 21-17 SET_ENQUEUE_DESTINATION Procedure Parameters

Parameter Description

rule_name

The name of the rule, specified as [schema_name.]rule_name. For example, to specify a rule named hr5 in the hr schema, enter hr.hr5 for this parameter. If the schema is not specified, then the current user is the default.

destination_queue_name

The name of the queue into which the apply component enqueues the message. Specify the queue in the form [schema_name.]queue_name. Only local queues can be specified.

For example, to specify a queue in the hr schema named streams_queue, enter hr.streams_queue. If the schema is not specified, then the current user is the default.

If NULL, then an existing name-value pair with the name APPLY$_ENQUEUE is removed. If no name-value pair exists with the name APPLY$_ENQUEUE for the rule, then no action is taken.

If non-NULL and a name-value pair already exists for the rule with the name APPLY$_ENQUEUE, then it is removed, and a new name-value pair with the value specified by this parameter is added.


Usage Notes

The following usage notes apply to this procedure:

The SET_ENQUEUE_DESTINATION Procedure and Apply Handlers

If an apply handler, such as a procedure DML handler, DDL handler, or message handler, processes a message that also is enqueued into a destination queue, then the apply handler processes the message before it is enqueued.

Considerations for the SET_ENQUEUE_DESTINATION Procedure

The following are considerations for using this procedure:

The SET_ENQUEUE_DESTINATION Procedure and XStream Outbound Servers

This procedure has no effect on XStream outbound servers.

The SET_ENQUEUE_DESTINATION Procedure and XStream Inbound Servers

This procedure functions the same way for apply processes and inbound servers.


SET_EXECUTE Procedure

This procedure specifies whether a message that satisfies the specified rule is executed by an apply component.

This procedure modifies the specified rule's action context to specify message execution. A rule action context is optional information associated with a rule that is interpreted by the client of the rules engine after the rule evaluates to TRUE for a message. In this case, the client of the rules engine is an apply component. The information in an action context is an object of type SYS.RE$NV_LIST, which consists of a list of name-value pairs.

A message execution directive specified by this procedure always consists of the following name-value pair in an action context:

Syntax

DBMS_APPLY_ADM.SET_EXECUTE(
  rule_name  IN  VARCHAR2,
  execute    IN  BOOLEAN);

Parameters

Table 21-18 SET_EXECUTE Procedure Parameters

Parameter Description

rule_name

The name of the rule, specified as [schema_name.]rule_name. For example, to specify a rule named hr5 in the hr schema, enter hr.hr5 for this parameter. If the schema is not specified, then the current user is the default.

execute

If TRUE, then the procedure removes the name-value pair with the name APPLY$_EXECUTE for the specified rule. Removing the name-value pair means that the apply component executes messages that satisfy the rule. If no name-value pair with name APPLY$_EXECUTE exists for the rule, then no action is taken.

If FALSE, then the procedure adds a name-value pair to the rule's action context. The name is APPLY$_EXECUTE and the value is NO. An apply component does not execute a message that satisfies the rule and does not send the message to any apply handler. If a name-value pair already exists for the rule with the name APPLY$_EXECUTE, then it is removed, and a new one with the value NO is added.

If NULL, then the procedure raises an error.


Usage Notes

The following usage notes apply to this procedure:

Considerations for the SET_EXECUTE Procedure

The following are considerations for using this procedure:

The SET_EXECUTE Procedure and XStream Outbound Servers

This procedure has no effect on XStream outbound servers.

The SET_EXECUTE Procedure and XStream Inbound Servers

This procedure functions the same way for apply processes and inbound servers.


SET_GLOBAL_INSTANTIATION_SCN Procedure

This procedure records the specified instantiation SCN for the specified source database and, optionally, for the schemas at the source database and the tables owned by these schemas. This procedure overwrites any existing instantiation SCN for the database, and, if it sets the instantiation SCN for a schema or a table, then it overwrites any existing instantiation SCN for the schema or table.

This procedure gives you precise control over which DDL logical change records (DDL LCRs) from a source database are ignored and which DDL LCRs are applied by an apply component.

Syntax

DBMS_APPLY_ADM.SET_GLOBAL_INSTANTIATION_SCN(
  source_database_name  IN  VARCHAR2,
  instantiation_scn     IN  NUMBER,
  apply_database_link   IN  VARCHAR2  DEFAULT NULL,
  recursive             IN  BOOLEAN   DEFAULT FALSE);

Parameters

Table 21-19 SET_GLOBAL_INSTANTIATION_SCN Procedure Parameters

Parameter Description

source_database_name

The global name of the source database. For example, DBS1.NET.

If you do not include the domain name, then the procedure appends it to the database name automatically. For example, if you specify DBS1 and the domain is NET, then the procedure specifies DBS1.NET automatically.

instantiation_scn

The instantiation SCN. Specify NULL to remove the instantiation SCN metadata for the source database from the data dictionary.

apply_database_link

The name of the database link to a non-Oracle database. This parameter should be set only when the destination database of a local apply component is a non-Oracle database.

recursive

If TRUE, then the procedure sets the instantiation SCN for the source database, all schemas in the source database, and all tables owned by the schemas in the source database. This procedure selects the schemas and tables from the ALL_USERS and ALL_TABLES data dictionary views, respectively, at the source database under the security context of the current user.

If FALSE, then the procedure sets the global instantiation SCN for the source database, but does not set the instantiation SCN for any schemas or tables

Note: If recursive is set to TRUE, then a database link from the destination database to the source database is required. This database link must have the same name as the global name of the source database and must be accessible to the current user. Also, a table must be accessible to the current user in either the ALL_TABLES or DBA_TABLES data dictionary view at the source database for this procedure to set the instantiation SCN for the table at the destination database.


Usage Notes

The following usage notes apply to this procedure:

Instantiation SCNs and DDL LCRs

If the commit SCN of a DDL LCR for a database object from a source database is less than or equal to the instantiation SCN for that source database at a destination database, then the apply component at the destination database disregards the DDL LCR. Otherwise, the apply component applies the DDL LCR.

The global instantiation SCN specified by this procedure is used for a DDL LCR only if the DDL LCR does not have object_owner, base_table_owner, and base_table_name specified. For example, the global instantiation SCN set by this procedure is used for DDL LCRs with a command_type of CREATE USER.

The recursive Parameter

If the recursive parameter is set to TRUE, then this procedure sets the instantiation SCN for each schema at a source database and for the tables owned by these schemas. This procedure uses the SET_SCHEMA_INSTANTIATION_SCN procedure to set the instantiation SCN for each schema, and it uses the SET_TABLE_INSTANTIATION_SCN procedure to set the instantiation SCN for each table. Each schema instantiation SCN is used for DDL LCRs on the schema, and each table instantiation SCN is used for DDL LCRs and row LCRs on the table.

If the recursive parameter is set to FALSE, then this procedure does not set the instantiation SCN for any schemas or tables.

Considerations for the SET_GLOBAL_INSTANTIATION_SCN Procedure

The following are considerations for using this procedure:

The SET_GLOBAL_INSTANTIATION_SCN Procedure and XStream Outbound Servers

Instantiation SCNs are not required for database objects processed by an outbound server. If an instantiation SCN is set for a database object, then the outbound server only sends the LCRs for the database object with SCN values that are greater than the instantiation SCN value. If a database object does not have an instantiation SCN set, then the outbound server skips the instantiation SCN check and sends all LCRs for that database object. In both cases, the outbound server only sends LCRs that satisfy its rule sets.

The apply_database_link parameter must be set to NULL or to the local database for this procedure to set an instantiation SCN for an outbound server.

See Also:

Oracle Database XStream Guide for more information about outbound servers and instantiation SCNs

The SET_GLOBAL_INSTANTIATION_SCN Procedure and XStream Inbound Servers

Inbound servers ignore instantiation SCNs. This procedure has no effect on XStream inbound servers.


SET_KEY_COLUMNS Procedures

This procedure records the set of columns to be used as the substitute primary key for apply purposes and removes existing substitute primary key columns for the specified object if they exist.

This procedure is overloaded. The column_list and column_table parameters are mutually exclusive.

Syntax

DBMS_APPLY_ADM.SET_KEY_COLUMNS(
   object_name          IN  VARCHAR2,
   column_list          IN  VARCHAR2,
   apply_database_link  IN  VARCHAR2  DEFAULT NULL);

DBMS_APPLY_ADM.SET_KEY_COLUMNS(
   object_name          IN  VARCHAR2,
   column_table         IN  DBMS_UTILITY.NAME_ARRAY,
   apply_database_link  IN  VARCHAR2  DEFAULT NULL);

Parameters

Table 21-20 SET_KEY_COLUMNS Procedure Parameters

Parameter Description

object_name

The name of the table specified as [schema_name.]object_name. For example, hr.employees. If the schema is not specified, then the current user is the default. If the apply component is applying changes to a non-Oracle database in a heterogeneous environment, then the object name is not verified.

column_list

A comma-delimited list of the columns in the table that you want to use as the substitute primary key, with no spaces between the column names.

If the column_list parameter is empty or NULL, then the current set of key columns is removed.

column_table

A PL/SQL index-by table of type DBMS_UTILITY.NAME_ARRAY of the columns in the table that you want to use as the substitute primary key. The index for column_table must be 1-based, increasing, dense, and terminated by a NULL.

If the column_table parameter is empty or NULL, then the current set of key columns is removed.

apply_database_link

The name of the database link to a non-Oracle database. This parameter should be set only when the destination database is a non-Oracle database.


Usage Notes

The following usage notes apply to this procedure:

Considerations for the SET_KEY_COLUMNS Procedure

The following are considerations for using this procedure:

Duplicate Rows and Substitute Primary Key Columns

A table has duplicate rows when all of the column values are identical for two or more rows in the table, excluding LOB, LONG, and LONG RAW columns. You can specify substitute primary key columns for a table at a destination database using by the SET_KEY_COLUMNS procedure. When substitute primary key columns are specified for a table with duplicate rows at a destination database, and the allow_duplicate_rows apply component parameter is set to Y, meet the following requirements to keep the table data synchronized at the source and destination databases:

The rest of this section provides more details about these requirements.

When there is no key for a table and the allow_duplicate_rows apply component parameter is set to Y, a single row LCR with an UPDATE or DELETE command type only is applied to one of the duplicate rows. In this case, if the table at the source database and the table at the destination database have corresponding duplicate rows, then a change that changes all of the duplicate rows at the source database also changes all the duplicate rows at the destination database when the row LCRs resulting from the change are applied.

For example, suppose a table at a source database has two duplicate rows. An update is performed on the duplicate rows, resulting in two row LCRs. At the destination database, one row LCR is applied to one of the duplicate rows. At this point, the rows are no longer duplicate at the destination database because one of the rows has changed. When the second row LCR is applied at the destination database, the rows are duplicate again. Similarly, if a delete is performed on these duplicate rows at the source database, then both rows are deleted at the destination database when the row LCRs resulting from the source change are applied.

When substitute primary key columns are specified for a table, row LCRs are identified with rows in the table during apply using the substitute primary key columns. If substitute primary key columns are specified for a table with duplicate rows at a destination database, and the allow_duplicate_rows apply component parameter is set to Y, then an update performed on duplicate rows at the source database can result in different changes when the row LCRs are applied at the destination database. Specifically, if the update does not change one of the columns specified as a substitute primary key column, then the same duplicate row can be updated multiple times at the destination database, while other duplicate rows might not be updated.

Also, if the substitute key columns do not identify each row in the table at the destination database uniquely, then a row LCR identified with multiple rows can update any one of the rows. In this case, the update in the row LCR might not be applied to the correct row in the table at the destination database.

An apply component ignores substitute primary key columns when it determines whether rows in a table are duplicates. An apply component determines that rows are duplicates only if all of the column values in the rows are identical (excluding LOB, LONG, and LONG RAW columns). Therefore, an apply component always raises an error if a single update or delete changes two or more nonduplicate rows in a table.

For example, consider a table with columns c1, c2, and c3 on which the SET_KEY_COLUMNS procedure is used to designate column c1 as the substitute primary key. If two rows have the same key value for the c1 column, but different value for the c2 or c3 columns, then an apply component does not treat the rows as duplicates. If an update or delete modifies more than one row because the c1 values in the rows are the same, then the apply component raises an error regardless of the setting for the allow_duplicate_rows apply component parameter.

See Also:

SET_PARAMETER Procedure for more information about the allow_duplicate_rows apply component parameter

The SET_KEY_COLUMNS Procedure and XStream Outbound Servers

This procedure has no effect on XStream outbound servers.

The SET_KEY_COLUMNS Procedure and XStream Inbound Servers

This procedure functions the same way for apply processes and inbound servers.


SET_PARAMETER Procedure

This procedure sets an apply parameter to the specified value.

Syntax

DBMS_APPLY_ADM.SET_PARAMETER (
   apply_name  IN  VARCHAR2, 
   parameter   IN  VARCHAR2, 
   value       IN  VARCHAR2  DEFAULT NULL);

Parameters

Table 21-21 SET_PARAMETER Procedure Parameters

Parameter Description

apply_name

The apply component name. Do not specify an owner.

parameter

The name of the parameter you are setting. See "Apply Component Parameters" for a list of these parameters.

value

The value to which the parameter is set.

If NULL, then the parameter is set to its default value.


Apply Component Parameters

The following table lists the parameters for an apply component.

Note:

Starting with Oracle Database 11g Release 2 (11.2.0.2), this subprogram includes the following new parameters: apply_sequence_nextval, compare_key_only, grouptransops, ignore_transaction, and max_sga_size.

Table 21-22 Apply Component Parameters

Parameter Name Possible Values Default Description

allow_duplicate_rows

Y or N

N

If Y and more than one row is changed by a single row logical change record (row LCR) with an UPDATE or DELETE command type, then the apply component only updates or deletes one of the rows.

If N, then the apply component raises an error when it encounters a single row LCR with an UPDATE or DELETE command type that changes more than one row in a table.

Note: Regardless of the setting for this parameter, apply components do not allow changes to duplicate rows for tables with LOB, LONG, or LONG RAW columns.

See Also: "Usage Notes" and "Duplicate Rows and Substitute Primary Key Columns"

apply_sequence_nextval

Y or N

N for apply processes

Y for XStream outbound servers and XStream inbound servers

Controls whether the apply component checks and adjusts sequence values.

If Y, then the apply component checks and adjusts sequence values.

For ascending sequences, setting this parameter to Y ensures that the destination sequence values are equal to or greater than the source sequence values.

For descending sequences, setting this parameter to Y ensures that the destination sequence values are equal to or less than the source sequence values.

If N, then the apply component does not check or adjust sequence values.

Note: This parameter is intended for XStream. Do not set this parameter to Y for an apply process in an Oracle Streams replication environment unless XStream capabilities are enabled by the DBMS_XSTREAM_ADM.ENABLE_GG_XSTREAM_FOR_STREAMS procedure. See Oracle Database XStream Guide for information about enabling XStream capabilities.

See Also: SET_PARAMETER Procedure for information about the capture_sequence_nextval capture process parameter

commit_serialization

DEPENDENT_TRANSACTIONS or FULL

DEPENDENT_TRANSACTIONS

The order in which applied transactions are committed.

Apply servers can apply nondependent transactions at the destination database in an order that is different from the commit order at the source database. Dependent transactions are always applied at the destination database in the same order as they were committed at the source database.

You control whether the apply servers can apply nondependent transactions in a different order at the destination database using the commit_serialization apply parameter. This parameter has the following settings:

  • DEPENDENT_TRANSACTIONS - The apply component can commit nondependent transactions in any order. Performance is best if you specify DEPENDENT_TRANSACTIONS.

  • FULL - The apply component commits applied transactions in the order in which they were committed at the source database.

Regardless of the specification, applied transactions can execute in parallel subject to data dependencies and constraint dependencies.

If you specify DEPENDENT_TRANSACTIONS, then it is possible that a destination database commits changes in a different order than the source database. For example, suppose two nondependent transactions are committed at the source database in the following order:

  1. Transaction A

  2. Transaction B

At the destination database, these transactions might be committed in the opposite order:

  1. Transaction B

  2. Transaction A

If you specify DEPENDENT_TRANSACTIONS and there are application constraints that are not enforced by the database, then use virtual dependency definitions or add RELY constraints to account for the application constraints. See Oracle Streams Concepts and Administration for information about virtual dependency definitions and Oracle Database Data Warehousing Guide for information about RELY constraints.

Note: The NONE value is deprecated for this parameter. It is replaced by the DEPENDENT_TRANSACTIONS value.

See Also: "Usage Notes"

compare_key_only

Y or N

N for apply processes

Y for XStream inbound servers

If Y, then disables automatic conflict detection and only uses primary and unique key columns to identify the table row for a row LCR.

If N, then enables automatic conflict detection and uses all of the old values in a row LCR to identify the table row for a row LCR.

Note: The COMPARE_OLD_VALUES procedure in this package can disable comparison of old values for specified columns during apply. See COMPARE_OLD_VALUES Procedure.

See Also: "Usage Notes" and Oracle Streams Replication Administrator's Guide for information about automatic conflict detection

disable_on_error

Y or N

Y

If Y, then the apply component is disabled on the first unresolved error, even if the error is not fatal.

If N, then the apply component continues regardless of unresolved errors.

See Also: "Usage Notes"

disable_on_limit

Y or N

N

If Y, then the apply component is disabled if the apply component terminates because it reached a value specified by the time_limit parameter or transaction_limit parameter.

If N, then the apply component is restarted immediately after stopping because it reached a limit.

When an apply component is restarted, it gets a new session identifier, and the processes associated with the apply component also get new session identifiers. However, the coordinator process number (APnn) remains the same.

grouptransops

A positive integer from 1 to 10000

250 for apply processes and XStream inbound servers

10000 for XStream outbound servers

The minimum number of LCRs that can be grouped into a single transaction. The commit LCR for a transaction is not included in the LCR count for the transaction.

This parameter enables an apply component to group LCRs from multiple transactions into a single transaction. The apply component groups only LCRs that are part of committed transactions.

If a transaction has more LCRs than the setting for this parameter, then the transaction is applied as a single transaction. The apply component does not split a transaction into separate transactions.

This parameter only takes effect if the parallelism parameter setting is 1. The grouptransops parameter is ignored if the parallelism parameter setting is greater than 1.

Note: This parameter is intended for XStream outbound servers and inbound servers. An Oracle Streams apply process ignores this parameter unless XStream capabilities are enabled by the DBMS_XSTREAM_ADM.ENABLE_GG_XSTREAM_FOR_STREAMS procedure. See Oracle Database XStream Guide for information about enabling XStream capabilities.

See Also: "Usage Notes"

ignore_transaction

A valid source transaction ID or NULL

NULL

Instructs the apply component to ignore the specified transaction from the source database, effective immediately.

Use caution when setting this parameter because ignoring a transaction might lead to data divergence between the source database and destination database.

To ignore multiple transactions, specify each transaction in a separate call to the SET_PARAMETER procedure. The DBA_APPLY_PARAMETERS view displays a comma-separated list of all transactions to be ignored. To clear the list of ignored transactions, run the SET_PARAMETER procedure and specify NULL for the ignore_transaction parameter.

If NULL, then the apply component ignores this parameter.

Note: An apply component ignores this parameter for transactions that were not captured by an Oracle Streams capture process.

See Also: "Usage Notes"

max_sga_size

A positive integer

NULL

Controls the amount of system global area (SGA) memory allocated specifically to the apply component, in megabytes.

The memory is allocated for the duration of the apply component's session and is released when the apply component becomes disabled.

If NULL, then the apply component ignores this parameter.

Note: This parameter is intended for XStream. Do not use this parameter in an Oracle Streams replication environment unless XStream capabilities are enabled by the DBMS_XSTREAM_ADM.ENABLE_GG_XSTREAM_FOR_STREAMS procedure. See Oracle Database XStream Guide for information about enabling XStream capabilities.

See Also: "Usage Notes"

maximum_scn

A valid SCN or INFINITE

INFINITE

The apply component is disabled before applying a transaction with a commit SCN greater than or equal to the value specified.

If INFINITE, then the apply component runs regardless of the SCN value.

See Also: "Usage Notes"

parallelism

A positive integer

4

The number of apply servers that can concurrently apply transactions.

The reader server and the apply server process names are ASnn, where nn can include letters and numbers. The total number of ASnn processes is the value of the parallelism parameter plus one.

For example, if parallelism is set to 4, then an apply component uses a total of five ASnn processes. In this case, there is one reader server and four apply servers.

Setting the parallelism parameter to a number higher than the number of available operating system user processes can disable the apply component. Make sure the PROCESSES initialization parameter is set appropriately when you set the parallelism parameter.

Note: When the value of this parameter is changed from 1 to a higher value for a running apply component, the apply component is stopped and restarted automatically. This can take some time depending on the size of the transactions currently being applied. When the value of this parameter is greater than 1, and the parameter value is decreased or increased, the apply component does not restart.

See Also: "Usage Notes"

preserve_encryption

Y or N

Y

Whether to preserve encryption for columns encrypted using transparent data encryption.

If Y, then columns in tables at the destination database must be encrypted when corresponding columns in row LCRs are encrypted. If columns are encrypted in row LCRs but the corresponding columns are not encrypted in the tables at the destination database, then an error is raised when the apply component tries to apply the row LCRs.

If N, then columns in tables at the destination database do not need to be encrypted when corresponding columns in row LCRs are encrypted. If columns are encrypted in row LCRs but the corresponding columns are not encrypted in the tables at the destination database, then the apply component applies the changes in the row LCRs.

Note: When the value of this parameter is changed for a running apply component, the apply component is stopped and restarted automatically. This can take some time depending on the size of the transactions currently being applied.

See Also: "Usage Notes"

rtrim_on_implicit_conversion

Y or N

Y

Whether to remove blank padding from the right end of a column when automatic data type conversion is performed during apply.

If Y, then blank padding is removed when a CHAR or NCHAR source column in a row LCR is converted to a VARCHAR2, NVARCHAR2, or CLOB column in a table.

If N, then blank padding is preserved in the column.

See Also: "Usage Notes" and Oracle Streams Concepts and Administration for information about automatic data type conversion during apply

startup_seconds

0, a positive integer, or INFINITE

0

The maximum number of seconds to wait for another instantiation of the same apply component to finish. If the other instantiation of the same apply component does not finish within this time, then the apply component does not start.

If INFINITE, then an apply component does not start until another instantiation of the same apply component finishes.

See Also: "Usage Notes"

time_limit

A positive integer or INFINITE

INFINITE

The apply component stops as soon as possible after the specified number of seconds since it started.

If INFINITE, then the apply component continues to run until it is stopped explicitly.

See Also: "Usage Notes"

trace_level

0 or a positive integer

0

Set this parameter only under the guidance of Oracle Support Services.

See Also: "Usage Notes"

transaction_limit

A positive integer or INFINITE

INFINITE

The apply component stops after applying the specified number of transactions.

If INFINITE, then the apply component continues to run regardless of the number of transactions applied.

See Also: "Usage Notes"

txn_age_spill_threshold

A positive integer or INFINITE

900

The apply component begins to spill messages from memory to hard disk for a particular transaction when the amount of time that any message in the transaction has been in memory exceeds the specified number. The parameter specifies the age in seconds.

When the reader server spills messages from memory, the messages are stored in a database table on the hard disk. These messages are not spilled from memory to a queue table.

Message spilling occurs at the transaction level. For example, if this parameter is set to 900, and the reader server of an apply component detects that one message in a transaction has been in memory longer than 900 seconds, then all of the messages in the transaction spill from memory to hard disk.

If INFINITE, then the apply component does not spill messages to the hard disk based on the age of the messages.

Query the DBA_APPLY_SPILL_TXN data dictionary view for information about transactions spilled by an apply component.

See Also: "Usage Notes"

txn_lcr_spill_threshold

A positive integer or INFINITE

10000

The apply component begins to spill messages from memory to hard disk for a particular transaction when the number of messages in memory for the transaction exceeds the specified number. The number of messages in first chunk of messages spilled from memory equals the number specified for this parameter, and the number of messages spilled in future chunks is either 100 or the number specified for this parameter, whichever is less.

If the reader server of an apply component has the specified number of messages in memory for a particular transaction, then when it detects the next message for this transaction, it spills the messages that are in memory to the hard disk. For example, if this parameter is set to 10000, and a transaction has 10,200 messages, then the reader server handles the transaction in the following way:

  1. Reads the first 10,000 messages in the transaction into memory

  2. Spills messages 1 - 10,000 to hard disk when it detects message 10,000

  3. Reads the next 100 messages in the transaction into memory

  4. Spills messages 10,001 - 10,100 to hard disk when it detects message 10,100

  5. Reads the next 100 messages in the transaction into memory

The apply component applies the first 10,100 messages from the hard disk and the last 100 messages from memory.

When the reader server spills messages from memory, the messages are stored in a database table on the hard disk. These messages are not spilled from memory to a queue table.

Message spilling occurs at the transaction level. For example, if this parameter is set to 10000, and the reader server of an apply component is assembling two transactions, one with 7,500 messages and another with 8,000 messages, then it does not spill any messages.

If INFINITE, then the apply component does not spill messages to the hard disk based on the number of messages in a transaction.

Query the DBA_APPLY_SPILL_TXN data dictionary view for information about transactions spilled by an apply component.

See Also: "Usage Notes"

write_alert_log

Y or N

Y

If Y, then the apply component writes a message to the alert log on exit.

If N, then the apply component does not write a message to the alert log on exit.

The message specifies the reason why the apply component stopped.


Usage Notes

The following usage notes apply to this procedure:

Delays Are Possible Before New Parameter Settings Take Effect

When you alter a parameter value, a short amount of time might pass before the new value for the parameter takes effect.

Parameters Interpreted as Positive Integers

For all parameters that are interpreted as positive integers, the maximum possible value is 4,294,967,295. Where applicable, specify INFINITE for larger values.

Parameters with a System Change Number (SCN) Setting

For parameters that require an SCN setting, any valid SCN value can be specified.

The SET_PARAMETER Procedure and XStream Outbound Servers

Outbound servers ignore the settings for the following apply parameters:

The commit_serialization parameter is always set to FULL for an outbound server, and the parallelism parameter is always set to 1 for an outbound server.

You can use the other apply parameters with outbound servers.

Note:

Using XStream requires purchasing a license for the Oracle GoldenGate product. See Oracle Database XStream Guide.

The SET_PARAMETER Procedure and XStream Inbound Servers

Inbound servers ignore the settings for the ignore_transaction and maximum_scn apply component parameters. You can use all of the other apply component parameters with inbound servers.

The default setting for the compare_key_only parameter for an inbound server is Y.

The default setting for the parallelism parameter for an inbound server is 4.

Note:

Using XStream requires purchasing a license for the Oracle GoldenGate product. See Oracle Database XStream Guide.

SET_SCHEMA_INSTANTIATION_SCN Procedure

This procedure records the specified instantiation SCN for the specified schema in the specified source database and, optionally, for the tables owned by the schema at the source database. This procedure overwrites any existing instantiation SCN for the schema, and, if it sets the instantiation SCN for a table, it overwrites any existing instantiation SCN for the table.

This procedure gives you precise control over which DDL logical change records (LCRs) for a schema are ignored and which DDL LCRs are applied by an apply component.

Syntax

DBMS_APPLY_ADM.SET_SCHEMA_INSTANTIATION_SCN(
  source_schema_name    IN  VARCHAR2,
  source_database_name  IN  VARCHAR2,
  instantiation_scn     IN  NUMBER,
  apply_database_link   IN  VARCHAR2  DEFAULT NULL,
  recursive             IN  BOOLEAN   DEFAULT FALSE);

Parameters

Table 21-23 SET_SCHEMA_INSTANTIATION_SCN Procedure Parameters

Parameter Description

source_schema_name

The name of the source schema. For example, hr.

When setting an instantiation SCN for schema, always specify the name of the schema at the source database, even if a rule-based transformation or apply handler is configured to change the schema name.

source_database_name

The global name of the source database. For example, DBS1.NET.

If you do not include the domain name, then the procedure appends it to the database name automatically. For example, if you specify DBS1 and the domain is NET, then the procedure specifies DBS1.NET automatically.

instantiation_scn

The instantiation SCN. Specify NULL to remove the instantiation SCN metadata for the source schema from the data dictionary.

apply_database_link

The name of the database link to a non-Oracle database. This parameter should be set only when the destination database of a local apply component is a non-Oracle database.

recursive

If TRUE, then the procedure sets the instantiation SCN for the specified schema and all tables owned by the schema in the source database. This procedure selects the tables owned by the specified schema from the ALL_TABLES data dictionary view at the source database under the security context of the current user.

If FALSE, then the procedure sets the instantiation SCN for specified schema, but does not set the instantiation SCN for any tables

Note: If recursive is set to TRUE, then a database link from the destination database to the source database is required. This database link must have the same name as the global name of the source database and must be accessible to the current user. Also, a table must be accessible to the current user in either the ALL_TABLES or DBA_TABLES data dictionary view at the source database for this procedure to set the instantiation SCN for the table at the destination database.


Usage Notes

The following usage notes apply to this procedure:

The SET_SCHEMA_INSTANTIATION_SCN Procedure and LCRs

Any instantiation SCN specified by this procedure is used only for LCRs captured by a capture process. It is not used for user-created LCRs.

Instantiation SCNs and DDL LCRs

If the commit SCN of a DDL LCR for a database object in a schema from a source database is less than or equal to the instantiation SCN for that database object at a destination database, then the apply component at the destination database disregards the DDL LCR. Otherwise, the apply component applies the DDL LCR.

The schema instantiation SCN specified by this procedure is used on the following types of DDL LCRs:

For example, the schema instantiation SCN set by this procedure is used for a DDL LCR with a command_type of CREATE TABLE and ALTER USER.

The schema instantiation SCN specified by this procedure is not used for DDL LCRs with a command_type of CREATE USER. A global instantiation SCN is needed for such DDL LCRs.

The recursive Parameter

If the recursive parameter is set to TRUE, then this procedure sets the table instantiation SCN for each table at the source database owned by the schema. This procedure uses the SET_TABLE_INSTANTIATION_SCN procedure to set the instantiation SCN for each table. Each table instantiation SCN is used for DDL LCRs and row LCRs on the table.

If the recursive parameter is set to FALSE, then this procedure does not set the instantiation SCN for any tables.

The SET_SCHEMA_INSTANTIATION_SCN Procedure and XStream Outbound Servers

Instantiation SCNs are not required for database objects processed by an outbound server. If an instantiation SCN is set for a database object, then the outbound server only sends the LCRs for the database object with SCN values that are greater than the instantiation SCN value. If a database object does not have an instantiation SCN set, then the outbound server skips the instantiation SCN check and sends all LCRs for that database object. In both cases, the outbound server only sends LCRs that satisfy its rule sets.

The apply_database_link parameter must be set to NULL or to the local database for this procedure to set an instantiation SCN for an outbound server.

See Also:

Oracle Database XStream Guide for more information about outbound servers and instantiation SCNs

The SET_SCHEMA_INSTANTIATION_SCN Procedure and XStream Inbound Servers

Inbound servers ignore instantiation SCNs. This procedure has no effect on XStream inbound servers.


SET_TABLE_INSTANTIATION_SCN Procedure

This procedure records the specified instantiation SCN for the specified table in the specified source database. This procedure overwrites any existing instantiation SCN for the particular table.

This procedure gives you precise control over which logical change records (LCRs) for a table are ignored and which LCRs are applied by an apply component.

Syntax

DBMS_APPLY_ADM.SET_TABLE_INSTANTIATION_SCN(
  source_object_name    IN  VARCHAR2,
  source_database_name  IN  VARCHAR2,
  instantiation_scn     IN  NUMBER,
  apply_database_link   IN  VARCHAR2  DEFAULT NULL);

Parameters

Table 21-24 SET_TABLE_INSTANTIATION_SCN Procedure Parameters

Parameter Description

source_object_name

The name of the source object specified as [schema_name.]object_name. For example, hr.employees. If the schema is not specified, then the current user is the default.

When setting an instantiation SCN for a database object, always specify the name of the schema and database object at the source database, even if a rule-based transformation or apply handler is configured to change the schema name or database object name.

source_database_name

The global name of the source database. For example, DBS1.NET.

If you do not include the domain name, then the procedure appends it to the database name automatically. For example, if you specify DBS1 and the domain is NET, then the procedure specifies DBS1.NET automatically.

instantiation_scn

The instantiation SCN. Specify NULL to remove the instantiation SCN metadata for the source table from the data dictionary.

apply_database_link

The name of the database link to a non-Oracle database. This parameter should be set only when the destination database of a local apply component is a non-Oracle database.


Usage Notes

The following usage notes apply to this procedure:

Instantiation SCNs and LCRs

If the commit SCN of an LCR for a table from a source database is less than or equal to the instantiation SCN for that table at some destination database, then the apply component at the destination database disregards the LCR. Otherwise, the apply component applies the LCR.

The table instantiation SCN specified by this procedure is used on the following types of LCRs:

For example, the table instantiation SCN set by this procedure is used for DDL LCRs with a command_type of ALTER TABLE or CREATE TRIGGER.

Note:

The instantiation SCN specified by this procedure is used only for LCRs captured by a capture process. It is not used for user-created LCRs.

The SET_TABLE_INSTANTIATION_SCN Procedure and XStream Outbound Servers

Instantiation SCNs are not required for database objects processed by an outbound server. If an instantiation SCN is set for a database object, then the outbound server only sends the LCRs for the database object with SCN values that are greater than the instantiation SCN value. If a database object does not have an instantiation SCN set, then the outbound server skips the instantiation SCN check and sends all LCRs for that database object. In both cases, the outbound server only sends LCRs that satisfy its rule sets.

The apply_database_link parameter must be set to NULL or to the local database for this procedure to set an instantiation SCN for an outbound server.

See Also:

Oracle Database XStream Guide for more information about outbound servers and instantiation SCNs

The SET_TABLE_INSTANTIATION_SCN Procedure and XStream Inbound Servers

Inbound servers ignore instantiation SCNs. This procedure has no effect on XStream inbound servers.


SET_UPDATE_CONFLICT_HANDLER Procedure

This procedure adds, modifies, or removes a prebuilt update conflict handler for the specified object.

Syntax

DBMS_APPLY_ADM.SET_UPDATE_CONFLICT_HANDLER(
   object_name          IN  VARCHAR2,
   method_name          IN  VARCHAR2,
   resolution_column    IN  VARCHAR2,
   column_list          IN  DBMS_UTILITY.NAME_ARRAY,
   apply_database_link  IN  VARCHAR2  DEFAULT NULL);

Parameters

Table 21-25 SET_UPDATE_CONFLICT_HANDLER Procedure Parameters

Parameter Description

object_name

The schema and name of the table, specified as [schema_name.]object_name, for which an update conflict handler is being added, modified, or removed.

For example, if an update conflict handler is being added for table employees owned by user hr, then specify hr.employees. If the schema is not specified, then the current user is the default.

method_name

Type of update conflict handler to create.

You can specify one of the prebuilt handlers, which determine whether the column list from the source database is applied for the row or whether the values in the row at the destination database are retained:

  • MAXIMUM: Applies the column list from the source database if it has the greater value for the resolution column. Otherwise, retains the values at the destination database.

  • MINIMUM: Applies the column list from the source database if it has the lesser value for the resolution column. Otherwise, retains the values at the destination database.

  • OVERWRITE: Applies the column list from the source database, overwriting the column values at the destination database.

  • DISCARD: Retains the column list from the destination database, discarding the column list from the source database.

If NULL, then the procedure removes any existing update conflict handler with the same object_name, resolution_column, and column_list. If non-NULL, then the procedure replaces any existing update conflict handler with the same object_name and resolution_column.

resolution_column

Name of the column used to uniquely identify an update conflict handler. For the MAXIMUM and MINIMUM prebuilt methods, the resolution column is also used to resolve the conflict. The resolution column must be one of the columns listed in the column_list parameter.

NULL is not allowed for this parameter. For the OVERWRITE and DISCARD prebuilt methods, you can specify any column in the column list.

column_list

List of columns for which the conflict handler is called.

The same column cannot be in more than one column list.

If a conflict occurs for one or more of the columns in the list when an apply component tries to apply a row logical change record (row LCR), then the conflict handler is called to resolve the conflict. The conflict handler is not called if a conflict occurs only for columns that are not in the list.

Note: Prebuilt update conflict handlers do not support LOB, LONG, LONG RAW, user-defined type, and Oracle-suppled type columns. Therefore, you should not include these types of columns in the column_list parameter.

apply_database_link

The name of the database link to a non-Oracle database. This parameter should be set only when the destination database is a non-Oracle database.

Note: Currently, conflict handlers are not supported when applying changes to a non-Oracle database.


Usage Notes

The following usage notes apply to this procedure:

See Also:

Oracle Streams Replication Administrator's Guide for more information about prebuilt and custom update conflict handlers

Modifying an Existing Update Conflict Handler

If you want to modify an existing update conflict handler, then you specify the table and resolution column of an the existing update conflict handler. You can modify the prebuilt method or the column list.

Removing an Existing Update Conflict Handler

If you want to remove an existing update conflict handler, then specify NULL for the prebuilt method and specify the table, column list, and resolution column of the existing update conflict handler.

Series of Actions for Conflicts

If an update conflict occurs, then Oracle completes the following series of actions:

  1. Calls the appropriate update conflict handler to resolve the conflict

  2. If no update conflict handler is specified or if the update conflict handler cannot resolve the conflict, then calls the appropriate error handler for the apply component, table, and operation to handle the error

  3. If no error handler is specified or if the error handler cannot resolve the error, then raises an error and moves the transaction containing the row LCR that caused the error to the error queue

    See Also:

    "Signature of a DML Handler Procedure or Error Handler Procedure" for information about setting an error handler

Procedure DML Handlers for Conflicts

If you cannot use a prebuilt update conflict handler to meet your requirements, then you can create a PL/SQL procedure to use as a custom conflict handler. You use the SET_DML_HANDLER procedure to designate one or more custom conflict handlers for a particular table. In addition, a custom conflict handler can process LOB columns and use LOB assembly.

A Column Can Be in Only One Column List

When a column is in a column list, and you try to add the same column to another column list, this procedure returns the following error:

ORA-00001: UNIQUE CONSTRAINT (SYS.APPLY$_CONF_HDLR_COLUMNS_UNQ1) VIOLATED

Update Conflict Handlers and Non-Oracle Databases

Setting an update conflict handler for an apply component that is applying to a non-Oracle database is not supported.

The SET_UPDATE_CONFLICT_HANDLER Procedure and XStream Outbound Servers

This procedure has no effect on XStream outbound servers.

The SET_UPDATE_CONFLICT_HANDLER Procedure and XStream Inbound Servers

This procedure functions the same way for apply processes and inbound servers.

Examples

The following is an example for setting an update conflict handler for the employees table in the hr schema:

DECLARE
  cols  DBMS_UTILITY.NAME_ARRAY;
BEGIN
  cols(1) := 'salary';
  cols(2) := 'commission_pct';
  DBMS_APPLY_ADM.SET_UPDATE_CONFLICT_HANDLER(
    object_name           =>  'hr.employees',
    method_name           =>  'MAXIMUM',
    resolution_column     =>  'salary',
    column_list           =>  cols);
END;
/

This example sets a conflict handler that is called if a conflict occurs for the salary or commission_pct column in the hr.employees table. If such a conflict occurs, then the salary column is evaluated to resolve the conflict. If a conflict occurs only for a column that is not in the column list, such as the job_id column, then this conflict handler is not called.


SET_VALUE_DEPENDENCY Procedure

This procedure sets or removes a value dependency. A value dependency is a virtual dependency definition that defines a relationship between the columns of two or more tables.

An apply component uses the name of a value dependencies to detect dependencies between row logical change records (row LCRs) that contain the columns defined in the value dependency. Value dependencies can define virtual foreign key relationships between tables, but, unlike foreign key relationships, value dependencies can involve more than two database objects.

This procedure is overloaded. The attribute_list and attribute_table parameters are mutually exclusive.

Syntax

DBMS_APPLY_ADM.SET_VALUE_DEPENDENCY(
   dependency_name IN VARCHAR2,
   object_name     IN VARCHAR2,
   attribute_list  IN VARCHAR2);

DBMS_APPLY_ADM.SET_VALUE_DEPENDENCY(
   dependency_name IN VARCHAR2,
   object_name     IN VARCHAR2,
   attribute_table IN DBMS_UTILITY.NAME_ARRAY);

Parameters

Table 21-26 SET_VALUE_DEPENDENCY Procedure Parameters

Parameter Description

dependency_name

The name of the value dependency.

If a dependency with the specified name does not exist, then it is created.

If a dependency with the specified name exists, then the specified object and attributes are added to the dependency.

If NULL, an error is raised.

object_name

The name of the table, specified as [schema_name.]table_name. For example, hr.employees. If the schema is not specified, then the current user is the default.

If NULL and the specified dependency exists, then the dependency is removed. If NULL and the specified dependency does not exist, then an error is raised.

If NULL, then attribute_list and attribute_table also must be NULL.

attribute_list

A comma-delimited list of column names in the table. There must be no spaces between entries.

attribute_table

A PL/SQL index-by table of type DBMS_UTILITY.NAME_ARRAY that contains names of columns in the table. The first column name should be at position 1, the second at position 2, and so on. The table does not need to be NULL terminated.


Usage Notes

The following usage notes apply to this procedure:

The SET_VALUE_DEPENDENCY Procedure and XStream Outbound Servers

This procedure has no effect on XStream outbound servers.

The SET_VALUE_DEPENDENCY Procedure and XStream Inbound Servers

This procedure functions the same way for apply processes and inbound servers.


START_APPLY Procedure

This procedure directs the apply component to start applying messages.

Syntax

DBMS_APPLY_ADM.START_APPLY(
   apply_name  IN  VARCHAR2);

Parameter

Table 21-27 START_APPLY Procedure Parameter

Parameter Description

apply_name

The apply component name. A NULL setting is not allowed. Do not specify an owner.


Usage Notes

The following usage notes apply to this procedure:

Apply Component Status

The apply component status is persistently recorded. Hence, if the status is ENABLED, then the apply component is started upon database instance startup. An apply component (annn) is an Oracle background process. The enqueue and dequeue state of DBMS_AQADM.START_QUEUE and DBMS_AQADM.STOP_QUEUE have no effect on the start status of an apply component.

The START_APPLY Procedure and XStream Outbound Servers

This procedure functions the same way for apply processes and outbound servers.

The START_APPLY Procedure and XStream Inbound Servers

This procedure functions the same way for apply processes and inbound servers.


STOP_APPLY Procedure

This procedure stops the apply component from applying messages and rolls back any unfinished transactions being applied.

Syntax

DBMS_APPLY_ADM.STOP_APPLY(
   apply_name  IN  VARCHAR2,
   force       IN  BOOLEAN   DEFAULT FALSE);

Parameters

Table 21-28 STOP_APPLY Procedure Parameters

Parameter Description

apply_name

The apply component name. A NULL setting is not allowed. Do not specify an owner.

force

If TRUE, then the procedure stops the apply component as soon as possible.

If FALSE, then the procedure stops the apply component after ensuring that there are no gaps in the set of applied transactions.

The behavior of the apply component depends on the setting specified for the force parameter and the setting specified for the commit_serialization apply component parameter. See "Usage Notes" for more information.


Usage Notes

The following usage notes apply to this procedure:

Apply Component Status

The apply component status is persistently recorded. Hence, if the status is DISABLED or ABORTED, then the apply component is not started upon database instance startup.

Queue Subprograms Have No Effect on Apply Component Status

The enqueue and dequeue state of DBMS_AQADM.START_QUEUE and DBMS_AQADM.STOP_QUEUE have no effect on the STOP status of an apply component.

The STOP_APPLY force Parameter and the commit_serialization Apply Parameter

The following table describes apply component behavior for each setting of the force parameter in the STOP_APPLY procedure and the commit_serialization apply component parameter. In all cases, the apply component rolls back any unfinished transactions when it stops.

force commit_serialization Apply Component Behavior
TRUE FULL The apply component stops immediately and does not apply any unfinished transactions.
TRUE DEPENDENT_TRANSACTIONS When the apply component stops, some transactions that have been applied locally might have committed at the source database at a later point in time than some transactions that have not been applied locally.
FALSE FULL The apply component stops after applying the next uncommitted transaction in the commit order, if any such transaction is in progress.
FALSE DEPENDENT_TRANSACTIONS Before stopping, the apply component applies all of the transactions that have a commit time that is earlier than the applied transaction with the most recent commit time.

For example, assume that the commit_serialization apply component parameter is set to DEPENDENT_TRANSACTIONS and there are three transactions: transaction 1 has the earliest commit time, transaction 2 is committed after transaction 1, and transaction 3 has the latest commit time. Also assume that an apply component has applied transaction 1 and transaction 3 and is in the process of applying transaction 2 when the STOP_APPLY procedure is run. Given this scenario, if the force parameter is set to TRUE, then transaction 2 is not applied, and the apply component stops (transaction 2 is rolled back). If, however, the force parameter is set to FALSE, then transaction 2 is applied before the apply component stops.

A different scenario would result if the commit_serialization apply component parameter is set to FULL. For example, assume that the commit_serialization apply component parameter is set to FULL and there are three transactions: transaction A has the earliest commit time, transaction B is committed after transaction A, and transaction C has the latest commit time. In this case, the apply component has applied transaction A and is in the process of applying transactions B and C when the STOP_APPLY procedure is run. Given this scenario, if the force parameter is set to TRUE, then transactions B and C are not applied, and the apply component stops (transactions B and C are rolled back). If, however, the force parameter is set to FALSE, then transaction B is applied before the apply component stops, and transaction C is rolled back.

See Also:

SET_PARAMETER Procedure for more information about the commit_serialization apply component parameter

The STOP_APPLY Procedure and XStream Outbound Servers

This procedure functions the same way for apply processes and outbound servers.

The STOP_APPLY Procedure and XStream Inbound Servers

This procedure functions the same way for apply processes and inbound servers.