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DBMS_CAPTURE_ADM

The DBMS_CAPTURE_ADM package, one of a set of Streams packages, provides administrative interfaces for starting, stopping, and configuring a capture process. The source of the captured changes is the redo logs, and the repository for the captured changes is a queue (created using the DBMS_STEAMS_ADM.SET_UP_QUEUE procedure or the DBMS_AQADM package).

See Also: Oracle Streams Concepts and Administration and Oracle Streams Replication Administrator's Guide for more information about this package and capture processes

This chapter contains the following topic:

• Summary of DBMS_CAPTURE_ADM Subprograms

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Summary of DBMS_CAPTURE_ADM Subprograms

Table 19-1  DBMS_CAPTURE_ADM Package Subprograms

Subprogram	Description
ABORT_GLOBAL_INSTANTIATION Procedure	Reverses the effects of running the PREPARE_GLOBAL_INSTANTIATION procedure
ABORT_SCHEMA_INSTANTIATION Procedure	Reverses the effects of running the PREPARE_SCHEMA_INSTANTIATION procedure
ABORT_TABLE_INSTANTIATION Procedure	Reverses the effects of running the PREPARE_TABLE_INSTANTIATION procedure
ALTER_CAPTURE Procedure	Alters a capture process
BUILD Procedure	Extracts the data dictionary of the current database to the redo logs and automatically specifies database supplemental logging for all primary key and unique key columns
CREATE_CAPTURE Procedure	Creates a capture process
DROP_CAPTURE Procedure	Drops a capture process
INCLUDE_EXTRA_ATTRIBUTE Procedure	Includes or excludes an extra attribute in logical change records (LCRs) captured by the specified capture process
PREPARE_GLOBAL_INSTANTIATION Procedure	Performs the synchronization necessary for instantiating all the tables in the database at another database
PREPARE_SCHEMA_INSTANTIATION Procedure	Performs the synchronization necessary for instantiating all tables in the schema at another database
PREPARE_TABLE_INSTANTIATION Procedure	Performs the synchronization necessary for instantiating the table at another database
SET_PARAMETER Procedure	Sets a capture process parameter to the specified value
START_CAPTURE Procedure	Starts the capture process, which mines redo logs and enqueues the mined redo information into the associated queue
STOP_CAPTURE Procedure	Stops the capture process from mining redo logs

Note: All procedures commit unless specified otherwise.

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ABORT_GLOBAL_INSTANTIATION Procedure

This procedure reverses the effects of running the PREPARE_GLOBAL_INSTANTIATION procedure. Specifically, running this procedure removes data dictionary information related to the database instantiation.

Syntax

DBMS_CAPTURE_ADM.ABORT_GLOBAL_INSTANTIATION();

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ABORT_SCHEMA_INSTANTIATION Procedure

This procedure reverses the effects of running the PREPARE_SCHEMA_INSTANTIATION procedure. Specifically, running this procedure removes data dictionary information related to the schema instantiation.

Syntax

DBMS_CAPTURE_ADM.ABORT_SCHEMA_INSTANTIATION(
   schema_name  IN  VARCHAR2);

Parameter

Table 19-2 ABORT_SCHEMA_INSTANTIATION Procedure Parameter

Parameter	Description
schema_name	The name of the schema for which to abort the effects of preparing instantiation.

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ABORT_TABLE_INSTANTIATION Procedure

This procedure reverses the effects of running the PREPARE_TABLE_INSTANTIATION procedure. Specifically, running this procedure removes data dictionary information related to the table instantiation.

Syntax

DBMS_CAPTURE_ADM.ABORT_TABLE_INSTANTIATION(
   table_name  IN  VARCHAR2);

Parameter

Table 19-3 ABORT_TABLE_INSTANTIATION Procedure Parameter

Parameter	Description
table_name	The name of the table for which to abort the effects of preparing instantiation, specified as [schema_name.]object_name. For example, hr.employees. If the schema is not specified, then the current user is the default.

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ALTER_CAPTURE Procedure

This procedure alters a capture process.

See Also: Oracle Streams Concepts and Administration for more information about altering a capture process

Syntax

DBMS_CAPTURE_ADM.ALTER_CAPTURE(
   capture_name              IN  VARCHAR2,
   rule_set_name             IN  VARCHAR2  DEFAULT NULL,
   remove_rule_set           IN  BOOLEAN   DEFAULT false,
   start_scn                 IN  NUMBER    DEFAULT NULL,
   use_database_link         IN  BOOLEAN   DEFAULT NULL,
   first_scn                 IN  NUMBER    DEFAULT NULL,
   negative_rule_set_name    IN  VARCHAR2  DEFAULT NULL,
   remove_negative_rule_set  IN  BOOLEAN   DEFAULT false,
   capture_user              IN  VARCHAR2  DEFAULT NULL);

Parameters

Table 19-4  ALTER_CAPTURE Procedure Parameters

Parameter	Description
capture_name	The name of the capture process being altered. You must specify an existing capture process name. Do not specify an owner.
rule_set_name	The name of the positive rule set for the capture process. The positive rule set contains the rules that instruct the capture process to capture changes. If you want to use a positive rule set for the capture process, 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_capture_rules, enter hr.job_capture_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 retains any existing positive rule set. If you specify NULL and the remove_rule_set parameter is set to true, then removes any existing positive rule set. See Also: Oracle Streams Concepts and Administration for more information about the changes that can be captured by a capture process
remove_rule_set	If true, then removes the positive rule set for the specified capture process. If you remove a positive rule set for a capture process, and the capture process does not have a negative rule set, then the capture process captures all supported changes to all objects in the database, excluding database objects in the SYS and SYSTEM schemas. If you remove a positive rule set for a capture process, and the capture process has a negative rule set, then the capture process captures all supported changes that are not discarded by the negative rule set. If false, then retains the positive rule set for the specified capture process. If the rule_set_name parameter is non-NULL, then this parameter should be set to false.
start_scn	A valid SCN for the database from which the capture process should start capturing changes. The SCN value specified must be greater than or equal to the first SCN for the capture process. An error is returned if an invalid SCN is specified.
use_database_link	If true, then specifies that the capture process at a downstream database uses a database link to the source database for administrative purposes relating to the capture process. If you want a capture process that is not using a database link currently to begin using a database link, then specify true. In this case, a database link with the same name as the global name of the source database must exist at the downstream database. If false, then specifies either that the capture process is running on the source database or that the capture process at a downstream database does not use a database link to the source database. If you want a capture process that is using a database link currently to stop using a database link, then specify false. In this case, you must prepare source database objects for instantiation manually when you add or change capture process rules that pertain to these objects. If NULL, then the current value of this parameter for the capture process is not changed.
first_scn	Specifies the lowest SCN in the redo log from which a capture process can capture changes. If you specify a new first SCN for the capture process, then the specified first SCN must meet the following requirements: It must be greater than the current first SCN for the capture process. It must be less than or equal to the current applied SCN for the capture process. However, this requirement does not apply if the current applied SCN for the capture process is zero. It must be less than or equal to the required checkpoint SCN for the capture process. An error is returned if the specified SCN does not meet the first three requirements. See "Usage Notes" for information about determining an SCN value that meets all of these conditions. When the first SCN is modified, the capture process purges information from its LogMiner data dictionary that is required to restart it at an earlier SCN. Also, if the specified first SCN is higher than the current start SCN for the capture process, then the start SCN is set automatically to the new value of the first SCN.
negative_rule_set_name	The name of the negative rule set for the capture process. The negative rule set contains the rules that instruct the capture process to discard changes. If you want to use a negative rule set for the capture process, 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_capture_rules, enter hr.neg_capture_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 retains any existing negative rule set. If you specify NULL and the remove_negative_rule_set parameter is set to true, then removes any existing negative rule set. If you specify both a positive and a negative rule set for a capture process, then the negative rule set is always evaluated first.
remove_negative_rule_set	If true, then removes the negative rule set for the specified capture process. If you remove a negative rule set for a capture process, and the capture process does not have a positive rule set, then the capture process captures all supported changes to all objects in the database, excluding database objects in the SYS and SYSTEM schemas. If you remove a negative rule set for a capture process, and a positive rule set exists for the capture process, then the capture process captures all changes that are not discarded by the positive rule set. If false, then retains the negative rule set for the specified capture process. If the negative_rule_set_name parameter is non-NULL, then this parameter should be set to false.
capture_user	The user who captures DML and DDL changes that satisfy the capture process rule sets. If NULL, then the capture user is not changed. To change the capture user, the user who invokes the ALTER_CAPTURE procedure must be granted DBA role. Only the SYS user can set the capture_user to SYS. If you change the capture user, then this procedure grants the new capture user enqueue privilege on the queue used by the capture process and configures the user as a secure queue user of the queue. In addition, make sure the capture user has the following privileges: Execute privilege on the rule sets used by the capture process Execute privilege on all rule-based transformation functions used in the rule set Execute privilege on all packages, including Oracle-supplied packages, that are invoked in rule-based transformations run by the capture process These privileges must be granted directly to the capture user. They cannot be granted through roles. By default, this parameter is set to the user who created the capture process by running either the CREATE_CAPTURE procedure in this package or one of the following procedures in the DBMS_STREAMS_ADM package with the streams_type parameter set to capture: ADD_GLOBAL_RULES ADD_SCHEMA_RULES ADD_TABLE_RULES ADD_SUBSET_RULES Note: If the specified user is dropped using DROP USER... CASCADE, then the capture_user setting for the capture process is set to NULL automatically. You must specify a capture user before the capture process can run.

Usage Notes

If you want to alter the first SCN for a capture process, then value specified must meet the conditions in the description for the first_scn parameter. The following query determines the current first SCN, applied SCN, and required checkpoint SCN for each capture process in a database:

SELECT CAPTURE_NAME, FIRST_SCN, APPLIED_SCN, REQUIRED_CHECKPOINT_SCN
   FROM DBA_CAPTURE;

Also, a capture process is stopped and restarted automatically when you change the value of one or more of the following ALTER_CAPTURE procedure parameters:

• start_scn
• capture_user

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BUILD Procedure

This procedure extracts the data dictionary of the current database to the redo log and automatically specifies database supplemental logging by running the following SQL statement:

ALTER DATABASE ADD SUPPLEMENTAL LOG DATA;

Syntax

DBMS_CAPTURE_ADM.BUILD(
   first_scn  OUT  NUMBER);

Note: This procedure is overloaded. One version of this procedure contains the OUT parameter first_scn, and the other does not.

Parameters

Table 19-5 BUILD Procedure Parameter

Parameter	Description
first_scn	Contains the lowest SCN value corresponding to the data dictionary extracted to the redo log that can be specified as a first SCN for a capture process

Usage Notes

You can run this procedure multiple times at a source database.

If you plan to capture changes originating at a source database with a capture process, then this procedure must be executed at the source database at least once. When the capture process is started, either at a local source database or at a downstream database, the capture process uses the extracted information in the redo log to create a LogMiner data dictionary.

After executing this procedure, you can query the FIRST_CHANGE# column of the V$ARCHIVED_LOG dynamic performance view where the DICTIONARY_BEGIN column is YES to determine the lowest SCN value for the database that can be specified as a first SCN for a capture process. The first SCN for a capture process is the lowest SCN in the redo log from which the capture process can capture changes.You can specify the first SCN for a capture process when you run the CREATE_CAPTURE or ALTER_CAPTURE procedure in the DBMS_CAPTURE_ADM package.

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CREATE_CAPTURE Procedure

This procedure creates a capture process.

See Also: Oracle Streams Concepts and Administration for more information about creating a capture process Chapter 82, "DBMS_RULE_ADM" for more information about rules and rule sets

Syntax

DBMS_CAPTURE_ADM.CREATE_CAPTURE(
   queue_name              IN  VARCHAR2,
   capture_name            IN  VARCHAR2,
   rule_set_name           IN  VARCHAR2  DEFAULT NULL,
   start_scn               IN  NUMBER    DEFAULT NULL,
   source_database         IN  VARCHAR2  DEFAULT NULL,
   use_database_link       IN  BOOLEAN   DEFAULT false,
   first_scn               IN  NUMBER    DEFAULT NULL,
   logfile_assignment      IN  VARCHAR2  DEFAULT 'implicit',
   negative_rule_set_name  IN  VARCHAR2  DEFAULT NULL,
   capture_user            IN  VARCHAR2  DEFAULT NULL); 

Parameters

Table 19-6  CREATE_CAPTURE Procedure Parameters

Parameter	Description
queue_name	The name of the queue into which the capture process enqueues changes. 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 capture process is created.
capture_name	The name of the capture process being created. A NULL specification is not allowed. Do not specify an owner. Note: The capture_name setting cannot be altered after the capture process is created.
rule_set_name	The name of the positive rule set for the capture process. The positive rule set contains the rules that instruct the capture process to capture changes. If you want to use a positive rule set for the capture process, 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_capture_rules, enter hr.job_capture_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 no negative rule set is specified, then the capture process captures all supported changes to all objects in the database, excluding database objects in the SYS and SYSTEM schemas. If you specify NULL, and a negative rule set exists for the capture process, then the capture process captures all changes that are not discarded by the negative rule set. See Also: Oracle Streams Concepts and Administration for more information about the changes that can be captured by a capture process
start_scn	A valid SCN for the database from which the capture process should start capturing changes. If the specified value is lower than the current SCN of the source database, then either the first_scn should be specified, or the SCN value specified for start_scn must be greater than or equal to the first SCN of an existing capture process which has taken at least one checkpoint. If start_scn is NULL and no value is specified for the first_scn parameter, then the database's current SCN is used as start SCN. If start_scn is NULL and a non-NULL value is specified for the first_scn parameter, then the first_scn value is used. If a value is specified for both start_scn and first_scn, then the start_scn value must be greater than or equal to the first_scn value. An error is returned if an invalid SCN is specified.
source_database	The global name of the source database. The source database is where the changes to be captured originated. If you do not include the domain name, then it is appended to the database name automatically. For example, if you specify DBS1 and the domain is .NET, then DBS1.NET is specified automatically. If NULL, or if the specified name is the same as the global name of the current database, then local capture is assumed and only the default values for use_database_link and first_scn can be specified.
use_database_link	If true, then specifies that the capture process at a downstream database uses a database link to the source database for administrative purposes relating to the capture process. The capture process uses the database link to prepare database objects for instantiation at the source database and run the DBMS_CAPTURE_ADM.BUILD procedure at the source database, if necessary. If false, then specifies either that the capture process is running on the source database or that the capture process at a downstream database does not use a database link to the source database. In this case, you must perform the following administrative tasks manually: Run the DBMS_CAPTURE_ADM.BUILD procedure at the source database to extract the data dictionary at the source database to the redo log when a capture process is created Obtain the first SCN for the downstream capture process if the first SCN is not specified during capture process creation. The first SCN is needed to create and maintain a capture process. Prepare source database objects for instantiation
first_scn	Specifies the lowest SCN in the redo log from which a capture process can capture changes. A non-NULL value for this parameter is valid only if the DBMS_CAPTURE_ADM.BUILD procedure has been run at least once at the source database. You can query the FIRST_CHANGE# column of the V$ARCHIVED_LOG dynamic performance view where the DICTIONARY_BEGIN column is YES to determine whether the DBMS_CAPTURE_ADM.BUILD procedure has been run on a source database. Any of the values returned by such a query can be used as a first_scn value if the redo log containing that SCN value is still available.
logfile_assignment	If implicit, the default, then the capture process at a downstream database scans all redo log files added by log transport services or manually from the source database to the downstream database. If explicit, then a redo log file is scanned by a capture process at a downstream database only if the capture process name is specified in the FOR logminer_session_name clause when the redo log file is added manually to the downstream database. If explicit, then log transport services cannot be used to add redo log files to the capture process being created. If you specify explicit for this parameter for a local capture process, then the local capture process cannot use the online redo log to find changes. In this case, the capture process must use the archived redo log. See Also: "Usage Notes" for information about adding redo log files manually
negative_rule_set_name	The name of the negative rule set for the capture process. The negative rule set contains the rules that instruct the capture process to discard changes. If you want to use a negative rule set for the capture process, 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_capture_rules, enter hr.neg_capture_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 capture process captures all supported changes to all objects in the database, excluding database objects in the SYS and SYSTEM schemas. If you specify NULL, and a positive rule set exists for the capture process, then the capture process captures all changes that are not discarded by the positive rule set. 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 a capture process, then the negative rule set is always evaluated first.
capture_user	The user who captures DML and DDL changes that satisfy the capture process rule sets. If NULL, then the user who runs the CREATE_CAPTURE procedure is used. Only a user who is granted DBA role can set a capture user. Only the SYS user can set the capture_user to SYS. Note: If the specified user is dropped using DROP USER... CASCADE, then the capture_user setting for the capture process is set to NULL automatically. You must specify a capture user before the capture process can run.

Usage Notes

The user who invokes this procedure must be granted DBA role.

The capture_user parameter specifies the user who captures changes that satisfy the capture process rule sets. This user must have the necessary privileges to capture changes. This procedure grants the capture user enqueue privilege on the queue used by the capture process and configures the user as a secure queue user of the queue.

In addition, make sure the capture user has the following privileges:

• Execute privilege on the rule sets used by the capture process
• Execute privilege on all rule-based transformation functions used in the rule set
• Execute privilege on all packages, including Oracle-supplied packages, that are invoked in rule-based transformations run by the capture process

These privileges must be granted directly to the capture user. They cannot be granted through roles.

Note: A capture user does not require privileges on a database object to capture changes to the database object. The capture process may pass these changes to a rule-based transformation function. Therefore, make sure you consider security implications when you configure a capture process. Creation of the first capture process in a database may take some time because the data dictionary is duplicated during this creation.

If you specify explicit for the logfile_assignment parameter, then you add a redo log file manually to a downstream database using the following statement:

ALTER DATABASE REGISTER LOGICAL LOGFILE 
file_name FOR capture_process;

Here, file_name is the name of the redo log file being added and capture_process is the name of the capture process that will use the redo log file at the downstream database. The capture_process is equivalent to the logminer_session_name and must be specified. The redo log file must be present at the site running the downstream database. You must transfer this file manually to the site running the downstream database using the DBMS_FILE_TRANSFER package, FTP, or some other transfer method.

See Also: Oracle Database SQL Reference for more information about the ALTER DATABASE statement and Oracle Data Guard Concepts and Administration for more information registering redo log files

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DROP_CAPTURE Procedure

This procedure drops a capture process.

See Also: "STOP_CAPTURE Procedure" Oracle Streams Concepts and Administration for more information about Streams data dictionary views

Syntax

DBMS_CAPTURE_ADM.DROP_CAPTURE(
   capture_name           IN  VARCHAR2,
   drop_unused_rule_sets  IN  BOOLEAN  DEFAULT false);

Parameters

Table 19-7 DROP_CAPTURE Procedure Parameters

Parameter	Description
capture_name	The name of the capture process being dropped. Specify an existing capture process name. Do not specify an owner.
drop_unused_rule_sets	If true, then drops any rule sets, positive and negative, used by the specified capture process if these rule sets are not used by any other Streams client, which includes capture processes, propagations, apply processes, 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 does not drop the rule sets used by the specified capture process, and the rule sets retain their rules.

Usage Notes

When you use this procedure to drop a capture process, information about rules created for the capture process using the DBMS_STREAMS_ADM package is removed from the data dictionary views for Streams rules. Information about such a rule is removed even if the rule is not in either rule set for the capture process.

The following are the data dictionary views for Streams rules:

• ALL_STREAMS_GLOBAL_RULES
• DBA_STREAMS_GLOBAL_RULES
• ALL_STREAMS_MESSAGE_RULES
• DBA_STREAMS_MESSAGE_RULES
• ALL_STREAMS_SCHEMA_RULES
• DBA_STREAMS_SCHEMA_RULES
• ALL_STREAMS_TABLE_RULES
• DBA_STREAMS_TABLE_RULES

  Note: A capture process must be stopped before it can be dropped.

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INCLUDE_EXTRA_ATTRIBUTE Procedure

This procedure includes or excludes an extra attribute in logical change records (LCRs) captured by the specified capture process.

Syntax

DBMS_CAPTURE_ADM.INCLUDE_EXTRA_ATTRIBUTE(
   capture_name    IN  VARCHAR2,
   attribute_name  IN  VARCHAR2,
   include         IN  BOOLEAN   DEFAULT true);

Parameters

Table 19-8 INCLUDE_EXTRA_ATTRIBUTE Procedure Parameters

Parameter	Description
capture_name	The name of the capture process. Specify an existing capture process name. Do not specify an owner.
attribute_name	The name of the attribute to be included in or excluded from LCRs captured by the capture process. The following names are valid settings: row_id The rowid of the row changed in a row LCR. This attribute is not included in DDL LCRs, nor in row LCRs for index-organized tables. The type is VARCHAR2. serial# The serial number of the session that performed the change captured in the LCR. The type is NUMBER. session# The identifier of the session that performed the change captured in the LCR. The type is NUMBER. thread# The thread number of the instance in which the change captured in the LCR was performed. Typically, the thread number is relevant only in a Real Application Clusters environment. The type is NUMBER. tx_name The name of the transaction that includes the LCR. The type is VARCHAR2. username The name of the user who performed the change captured in the LCR. The type is VARCHAR2.
include	If true, then the specified attribute is included in LCRs captured by the capture process If false, then the specified attribute is excluded from LCRs captured by the capture process

Usage Notes

The redo log contains information about each change made to a database, and some of this information is not captured by a capture process unless you use this procedure to instruct a capture process to capture it. This procedure enables you to specify extra information in the redo log that a capture process should capture. If you want to exclude an extra attribute that is being captured by a capture process, then specify the attribute and specify false for the include parameter.

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PREPARE_GLOBAL_INSTANTIATION Procedure

This procedure performs the synchronization necessary for instantiating all the tables in the database at another database.

This procedure records the lowest SCN of each object in the database for instantiation. SCNs subsequent to the lowest SCN for an object can be used for instantiating the object. Running this procedure prepares all current and future objects in the database for instantiation.

Syntax

DBMS_CAPTURE_ADM.PREPARE_GLOBAL_INSTANTIATION;

Usage Notes

Run this procedure at the source database.

If you use a capture process to capture all of the changes to a database, then use this procedure to prepare the tables in the database for instantiation after the capture process has been configured.

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PREPARE_SCHEMA_INSTANTIATION Procedure

This procedure performs the synchronization necessary for instantiating all tables in the schema at another database.

This procedure records the lowest SCN of each object in the schema for instantiation. SCNs subsequent to the lowest SCN for an object can be used for instantiating the object. Running this procedure prepares all current and future objects in the schema for instantiation.

Syntax

DBMS_CAPTURE_ADM.PREPARE_SCHEMA_INSTANTIATION(
   schema_name  IN  VARCHAR2);

Parameter

Table 19-9 PREPARE_SCHEMA_INSTANTIATION Procedure Parameter

Parameter	Description
schema_name	The name of the schema. For example, hr.

Usage Notes

Run this procedure at the source database. If you use a capture process to capture all of the changes to schema, then use this procedure to prepare the tables in the schema for instantiation after the capture process has been configured.

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PREPARE_TABLE_INSTANTIATION Procedure

This procedure performs the synchronization necessary for instantiating the table at another database.

This procedure records the lowest SCN of the table for instantiation. SCNs subsequent to the lowest SCN for an object can be used for instantiating the object.

Syntax

DBMS_CAPTURE_ADM.PREPARE_TABLE_INSTANTIATION(
   table_name  IN  VARCHAR2);

Parameters

Table 19-10 PREPARE_TABLE_INSTANTIATION Procedure Parameter

Parameter	Description
table_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.

Usage Notes

Run this procedure at the source database. If you use a capture process to capture all of the changes to schema, then use this procedure to prepare the tables in the schema for instantiation after the capture process has been configured.

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SET_PARAMETER Procedure

This procedure sets a capture process parameter to the specified value.

Syntax

DBMS_CAPTURE_ADM.SET_PARAMETER(
   capture_name  IN  VARCHAR2,
   parameter     IN  VARCHAR2,
   value         IN  VARCHAR2);

Parameters

Table 19-11 SET_PARAMETER Procedure Parameters

Parameter	Description
capture_name	The name of the capture process. Do not specify an owner. The capture process uses LogMiner to capture changes from the redo logs.
parameter	The name of the parameter you are setting. See "Capture Process Parameters" for a list of these parameters.
value	The value to which the parameter is set

Usage Notes

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

Capture Process Parameters

The following table lists the parameters for the capture process.

Table 19-12  Capture Process Parameters

Parameter Name	Possible Values	Default	Description
disable_on_limit	Y or N	N	If Y, then the capture process is disabled if the capture process terminates because it reached a value specified by the time_limit parameter or message_limit parameter. If N, then the capture process is restarted immediately after stopping because it reached a limit.
maximum_scn	A valid SCN or infinite	infinite	The capture process is disabled before capturing a change record with an SCN greater than or equal to the value specified. If infinite, then the capture process runs regardless of the SCN value.
message_limit	A positive integer or infinite	infinite	The capture process stops after capturing the specified number of messages. If infinite, then the capture process continues to run regardless of the number of messages captured.
parallelism	A positive integer	1	The number of parallel execution servers that may concurrently mine the redo log Note: When you change the value of this parameter, the capture process is stopped and restarted automatically. Setting the parallelism parameter to a number higher than the number of available parallel execution servers may disable the capture process. Make sure the PROCESSES and PARALLEL_MAX_SERVERS initialization parameters are set appropriately when you set the parallelism capture process parameter.
startup_seconds	0, a positive integer, or infinite	0	The maximum number of seconds to wait for another instantiation of the same capture process to finish. If the other instantiation of the same capture process does not finish within this time, then the capture process does not start. This parameter is useful only if you are starting the capture process manually. If infinite, then a capture process does not start until another instantiation of the same capture process finishes.
time_limit	A positive integer or infinite	infinite	The capture process stops as soon as possible after the specified number of seconds since it started. If infinite, then the capture process continues to run until it is stopped explicitly.
trace_level	0 or a positive integer	0	Set this parameter only under the guidance of Oracle Support Services.
write_alert_log	Y or N	Y	If Y, then the capture process writes a message to the alert log on exit. If N, then the capture process does not write a message to the alert log on exit. The message specifies the reason the capture process stopped.

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

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START_CAPTURE Procedure

This procedure starts the capture process, which mines redo logs and enqueues the mined redo information into the associated queue.

The start status is persistently recorded. Hence, if the status is ENABLED, then the capture process is started upon database instance startup.

The capture process is a background Oracle process and is prefixed by c.

The enqueue and dequeue state of DBMS_AQADM.START_QUEUE and DBMS_AQADM.STOP_QUEUE have no effect on the start status of a capture process.

See Also: Chapter 96, "DBMS_STREAMS_ADM"

Syntax

DBMS_CAPTURE_ADM.START_CAPTURE(
   capture_name  IN  VARCHAR2);

Parameters

Table 19-13 START_CAPTURE Procedure Parameter

Parameter	Description
capture_name	The name of the capture process. Do not specify an owner. The capture process uses LogMiner to capture changes in the redo information. A NULL setting is not allowed.

Usage Notes

You can create the capture process using the following procedures:

• DBMS_CAPTURE_ADM.CREATE_CAPTURE
• DBMS_STREAMS_ADM.ADD_GLOBAL_RULES
• DBMS_STREAMS_ADM.ADD_SCHEMA_RULES
• DBMS_STREAMS_ADM.ADD_TABLE_RULES

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STOP_CAPTURE Procedure

This procedure stops the capture process from mining redo logs.

The stop status is persistently recorded. Hence, if the status is DISABLED, then the capture process is not started upon database instance startup.

The enqueue and dequeue state of DBMS_AQADM.START_QUEUE and DBMS_AQADM.STOP_QUEUE have no effect on the stop status of a capture process.

Syntax

DBMS_CAPTURE_ADM.STOP_CAPTURE(
   capture_name  IN  VARCHAR2,
   force         IN  BOOLEAN  DEFAULT false);

Parameters

Table 19-14 STOP_CAPTURE Procedure Parameters

Parameter	Description
capture_name	The name of the capture process. A NULL setting is not allowed. Do not specify an owner.
force	This parameter is reserved for future use. In the current release, valid BOOLEAN settings are ignored.