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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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85 DBMS_LOGSTDBY

The DBMS_LOGSTDBY package provides subprograms for configuring and managing the logical standby database environment.

See Also:

Oracle Data Guard Concepts and Administration for more information about SQL Apply and logical standby databases

This chapter contains the following topics:


Using DBMS_LOGSTDBY

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


Overview

The DBMS_LOGSTDBY package helps you manage the SQL Apply (logical standby database) environment. The subprograms in the DBMS_LOGSTDBY package help you to accomplish the following main objectives:


Secutity Model

You must have the DBA role to use the DBMS_LOGSTDBY package.

A prototype role, LOGSTDBY_ADMINISTRATOR, is created by default with RESOURCE, and EXECUTE privileges on DBMS_LOGSTDBY. If you choose to use this role, consider granting ALTER DATABASE and ALTER SESSION privileges to the role so that the grantee can start and stop SQL Apply and can enable and disable the database guard.

The procedures associated with skipping transactions (SKIP and UNSKIP, SKIP_ERROR and UNSKIP_ERROR, and SKIP_TRANSACTION and UNSKIP_TRANSACTION) all require DBA privileges to execute because their scope may contain wildcard schemas. Oracle recommends that where SKIP procedures are specified, these be owned by a secure account with appropriate privileges on the schemas they act on (for example, SYS).


Summary of DBMS_LOGSTDBY Subprograms

Table 85-1 DBMS_LOGSTDBY Package Subprograms

Subprogram Description

APPLY_SET Procedure

Sets the values of various parameters that configure and maintain SQL Apply

APPLY_UNSET Procedure

Restores the default values of various parameters that configure and maintain SQL Apply

BUILD Procedure

Ensures supplemental logging is enabled properly and builds the LogMiner dictionary

INSTANTIATE_TABLE Procedure

Creates and populates a table in the standby database from a corresponding table in the primary database

IS_APPLY_SERVER Function

This function returns TRUE if it is executed from PL/SQL in the context of a logical standby apply server process. This function is used in conjunction with triggers that have the fire_once parameter in the DBMS_DDL.SET_TRIGGER_FIRING_PROPERTY subprogram set to FALSE (the default is TRUE). Such triggers are executed when the relevant target is updated by an apply process. This function can be used within the body of the trigger to ensure that the trigger takes different (or no) actions on the primary or on the standby.

MAP_PRIMARY_SCN Function

Maps an SCN relevant to the primary database to a corresponding SCN at the logical standby database. The mapped SCN is conservative in nature, and can thus be used to flash back the logical standby database to compensate for a flashback database operation performed at the primary database.

PREPARE_FOR_NEW_PRIMARY Procedure

Used after a failover, this procedure ensures a local logical standby database that was not involved in the failover has not processed more redo than the new primary database and reports the set of archive redo log files that must be replaced to ensure consistency

PURGE_SESSION Procedure

Identifies the archived redo log files that have been applied to the logical standby database and are no longer needed by SQL Apply

REBUILD Procedure

Records relevant metadata (including the LogMiner dictionary) in the redo stream in case a database that has recently changed its role to a primary database following a failover operation fails to do so during the failover process

SET_TABLESPACE Procedure

Moves metadata tables required by SQL Apply to the user-specified tablespace. By default, the metadata tables are created in the SYSAUX tablespace.

SKIP Procedure

Specifies rules that control database operations that should not be applied to the logical standby database

SKIP_ERROR Procedure

Specifies rules regarding what action to take upon encountering errors

SKIP_TRANSACTION Procedure

Specifies transactions that should not be applied on the logical standby database. Be careful in using this procedure, because not applying specific transactions may cause data corruption at the logical standby database.

UNSKIP Procedure

Deletes rules specified by the SKIP procedure

UNSKIP_ERROR Procedure

Deletes rules specified by the SKIP_ERROR procedure

UNSKIP_TRANSACTION Procedure

Deletes rules specified by the SKIP_TRANSACTION procedure



APPLY_SET Procedure

Use this procedure to set values of parameters that configure and manage SQL Apply in a logical standby database environment. All parameters, except for PRESERVE_COMMIT_ORDER, can be changed without having to stop SQL Apply.

Syntax

DBMS_LOGSTDBY.APPLY_SET (
     inname             IN VARCHAR,
     value              IN VARCHAR);

Parameters

Table 85-2 APPLY_SET Procedure Parameters

Parameter Description

APPLY_SERVERS

Controls the number of APPLIER processes used to apply changes. The maximum number allowed is 1024, provided the MAX_SERVERS parameter is set to accommodate this.

EVENT_LOG_DEST

Controls where SQL Apply records the occurrence of an interesting event. It takes the following values:

  • DEST_ALL - All events will be recorded in the DBA_LOGSTDBY_EVENTS view and in the alert log.

  • DEST_EVENTS_TABLE - All events that contain information about user data will be recorded only in the DBA_LOGSTDBY_EVENTS view. This is the default value.

For example, if SQL Apply receives an ORA-1403 error, the whole event is recorded in the DBA_LOGSTDBY_EVENTS view. Whereas, the alert log records only that SQL Apply stopped because of ORA-1403. No information regarding the user table or offending statement is logged in the alert log. However, if you stop the SQL Apply engine, it gets recorded in both the DBA_LOGSTDBY_EVENTS view and in the alert log.

Note that this parameter affects the behavior of the following parameters: RECORD_APPLIED_DDL, RECORD_SKIP_DDL, RECORD_SKIP_ERRORS, and RECORD_UNSUPPORTED_OPERATIONS. For example, if RECORD_APPLIED_DDL is set to TRUE, but EVENT_LOG_DEST is set to DEST_EVENTS_TABLE, then the applied DDL string will only be recorded in the DBA_LOGSTDBY_EVENTS view.

LOG_AUTO_DEL_RETENTION_TARGET

This parameter setting is only meaningful if LOG_AUTO_DELETE has been set to TRUE. The value you supply for this parameter controls how long (in minutes) a remote archived log that is received from the primary database will be retained at the logical standby database once all redo records contained in the log have been applied at the logical standby database. The default value is 1440 minutes.

LOG_AUTO_DELETE

Automatically deletes archived redo log files once they have been applied on the logical standby database. Set to TRUE to enable automatic deletion of archived redo log files, and FALSE to disable automatic deletion.The default value is TRUE.

MAX_EVENTS_RECORDED

Number of recent events that will be visible through the DBA_LOGSTDBY_EVENTS view. To record all events encountered by SQL Apply, use the DBMS_LOGSTDBY.MAX_EVENTS constant as the number value. The default value is 10,000.

MAX_SERVERS

Number of processes that SQL Apply uses to read and apply redo. The default value is 9. The maximum number allowed is 2048.

MAX_SGA

Number of megabytes from shared pool in System Global Area (SGA) that SQL Apply will use. The default value is 30 megabytes or one quarter of the value set for SHARED_POOL_SIZE, whichever is lower. The maximum size allowed is 4095 megabytes.

PREPARE_SERVERS

Controls the number of PREPARER processes used to prepare changes. The maximum number allowed is 1024, provided the MAX_SERVERS parameter is set to accommodate this.

PRESERVE_COMMIT_ORDER

TRUE: Transactions are applied to the logical standby database in the exact order in which they were committed on the primary database. This is the default parameter setting.

FALSE: Transactions containing non-overlapping sets of rows may be committed in a different order than they were committed on the primary database.

Regardless of the level chosen, modifications done to the same row are always applied in the same order as they happened on the primary database. See the Usage Notes for details and recommendations.

You cannot modify this parameter while SQL Apply is running.

RECORD_APPLIED_DDL

Controls whether DDL statements that have been applied to the logical standby database are recorded in the location specified by the EVENT_LOG_DEST parameter. Specify one of the following values:

TRUE: Indicates that DDL statements applied to the logical standby database are recorded in the DBA_LOGSTDBY_EVENTS table and the alert log.

FALSE: Indicates that applied DDL statements are not recorded. This is the default parameter setting.

RECORD_SKIP_DDL

Controls whether skipped DDL statements are recorded in the location specified by the EVENT_LOG_DEST parameter. Specify one of the following values:

TRUE: Skipped DDL statements are recorded in the DBA_LOGSTDBY_EVENTS table and the alert log. This is the default parameter setting.

FALSE: Skipped DDL statements are not recorded in the DBA_LOGSTDBY_EVENTS table and the alert log.

RECORD_SKIP_ERRORS

Controls whether skipped errors (as described by the SKIP_ERROR procedure) are recorded in the location specified by the EVENT_LOG_DEST parameter. Specify one of the following values:

TRUE: Skipped errors are recorded in the DBA_LOGSTDBY_EVENTS table and the alert log. This is the default parameter setting.

FALSE: Skipped errors are not recorded in the DBA_LOGSTDBY_EVENTS table and the alert log.

RECORD_UNSUPPORTED_OPERATIONS

Captures information about transactions running on the primary database that will not be supported by a logical standby database. This procedure records its information as events in the DBA_LOGSTDBY_EVENTS table.


If a parameter is changed while SQL Apply is running, the change will take effect at some point in the future. In such a case, an informational row is inserted into the DBA_LOGSTDBY_EVENTS view at the time the parameter change takes effect.

Additionally, if you are modifying a parameter while SQL Apply is running on an Oracle RAC configuration, you must be connected to the same instance where SQL Apply is running.

Exceptions

Table 85-3 APPLY_SET Procedure Exceptions

Exception Description

ORA-16103

Logical Standby apply must be stopped to allow this operation

ORA-16104

invalid Logical Standby option requested

ORA-16236

Logical Standby metadata operation in progress


Usage Notes

Examples

To record DDLs in the DBA_LOGSTDBY_EVENTS view and in the alert log, issue the following statement:

SQL> EXECUTE DBMS_LOGSTDBY.APPLY_SET('RECORD_APPLIED_DDL', TRUE);

APPLY_UNSET Procedure

Use the APPLY_UNSET procedure to restore the default values of the parameters that you changed with the APPLY_SET procedure.

Syntax

DBMS_LOGSTDBY.APPLY_UNSET (
     inname          IN VARCHAR);

Parameters

The parameter information for the APPLY_UNSET procedure is the same as that described for the APPLY_SET procedure. See Table 85-2 for complete parameter information.

Exceptions

Table 85-4 APPLY_UNSET Procedure Exceptions

Exception Description

ORA-16103

Logical Standby apply must be stopped to allow this operation

ORA-16104

invalid Logical Standby option requested

ORA-16236

Logical Standby metadata operation in progress


Usage Notes

Examples

If you previously specified that applied DDLs show up in the DBA_LOGSTDBY_EVENTS view and the alert log, you can restore the default behavior of SQL Apply regarding applied DDL statements with the following statement:

SQL> EXECUTE DBMS_LOGSTDBY.APPLY_UNSET('RECORD_APPLIED_DDL');

BUILD Procedure

Use this procedure on the primary database to record relevant metadata (LogMiner dictionary) information in the redo log, which will subsequently be used by SQL Apply. This procedure will enable database-wide primary- and unique-key supplemental logging, if necessary.

Syntax

DBMS_LOGSTDBY.BUILD;

Usage Notes

Examples

To build the LogMiner dictionary in the redo stream of the primary database and to record additional information so that a logical standby database can be instantiated, issue the following SQL statement at the primary database

SQL> EXECUTE DBMS_LOGSTDBY.BUILD;

INSTANTIATE_TABLE Procedure

This procedure creates and populates a table in the standby database from a corresponding table in the primary database. The table requires the name of the database link (dblink) as an input parameter. If the table already exists in the logical standby database, it will be dropped and re-created based on the table definition at the primary database. This procedure only brings over the data associated with the table, and not the associated indexes and constraints.

Use the INSTANTIATE_TABLE procedure to:

Syntax

DBMS_LOGSTDBY.INSTANTIATE_TABLE (
     schema_name         IN VARCHAR2,
     table_name          IN VARCHAR2,
     dblink              IN VARCHAR2);

Parameters

Table 85-5 INSTANTIATE_TABLE Procedure Parameters

Parameter Description

schema_name

Name of the schema

table_name

Name of the table to be created or re-created in the standby database

dblink

Name of the database link account that has privileges to read and lock the table in the primary database, as well as the SELECT_CATALOG_ROLE on the primary database


Exceptions

Table 85-6 INSTANTIATE_TABLE Procedure Exceptions

Exception Description

ORA-16103

Logical Standby apply must be stopped to allow this operation

ORA-16236

Logical Standby metadata operation in progress

ORA-16276

Specified database link does not correspond to primary database

ORA-16277

Specified table is not supported by logical standby database

ORA-16278

Specified table has a multi-object skip rule defined


Usage Notes

Examples

SQL> EXECUTE DBMS_LOGSTDBY.INSTANTIATE_TABLE (-
     SCHEMA_NAME => 'HR', TABLE_NAME => 'EMPLOYEES', -
     DBLINK => 'INSTANTIATE_TBL_LINK');

IS_APPLY_SERVER Function

This function returns TRUE if it is executed from PL/SQL in the context of a logical standby apply server process. This function is used in conjunction with triggers that have the fire_once parameter in the DBMS_DDL.SET_TRIGGER_FIRING_PROPERTY subprogram set to FALSE (the default is TRUE). Such triggers are executed when the relevant target is updated by an apply process. This function can be used within the body of the trigger to ensure that the trigger takes different (or no) actions on the primary or on the standby.

See Also:

Oracle Database PL/SQL Packages and Types Reference for more information about the DBMS_DDL.SET_TRIGGER_FIRING_PROPERTY subprogram.

Syntax

DBMS_LOGSTDBY.IS_APPLY_SERVER
RETURN BOOLEAN;

Parameters

None


MAP_PRIMARY_SCN Function

Returns an SCN on the standby that predates the supplied SCN from the primary database by at least 5 minutes. This function can be used to determine a safe SCN to use in a compensating flashback database operation at the logical standby database, following a flashback database operation or a point-in-time recovery operation at the primary database.

Syntax

DBMS_LOGSTDBY.MAP_PRIMARY_SCN(primary_scn NUMBER) RETURN NUMBER;

Exceptions

Table 85-7 MAP_PRIMARY_SCN Function Exceptions

Exception Description

ORA-20001

Primary SCN is before mapped range

ORA-20002

SCN mapping requires PRESERVE_COMMIT_ORDER to be TRUE


Usage Notes

Use this function to get a conservative SCN at the logical standby database that corresponds to an SCN at the primary database. This function is useful in the context of doing compensating flashback database operations at the logical standby following a flashback database or a point-in-time recovery operation done at the primary database.


PREPARE_FOR_NEW_PRIMARY Procedure

The PREPARE_FOR_NEW_PRIMARY procedure must be invoked at a logical standby database following a failover if that standby database was not the target of the failover operation. Such a standby database must process the exact same set of redo logs processed at the new primary database. This routine ensures that the local logical standby database has not processed more redo than the new primary database and reports the set of archive logs that must be replaced to ensure consistency. The set of replacement logs will be reported in the alert.log. These logs must be copied to the logical standby and registered using the ALTER DATABASE REGISTER LOGICAL LOGFILE statement.

Syntax

DBMS_LOGSTDBY.PREPARE_FOR_NEW_PRIMARY (
           FORMER_STANDBY_TYPE         IN VARCHAR2,
           DBLINK                      IN VARCHAR2);

Parameters

Table 85-8 PREPARE_FOR_NEW_PRIMARY Procedure Parameters

Parameter Description

FORMER_STANDBY_TYPE

The type of standby database that was the target of the failover operation to become the new primary database. Valid values are 'PHYSICAL' if the new primary was formerly a physical standby, and 'LOGICAL' if the new primary database was formerly a logical standby database.

DBLINK

The name of a database link to the new primary database


Exceptions

Table 85-9 PREPARE_FOR_NEW_PRIMARY Procedure Exceptions

Exception Description

ORA-16104

Invalid Logical Standby option.

ORA-16109

Failed to apply log data from previous primary.


Usage Notes

Examples

SQL> EXECUTE DBMS_LOGSTDBY.PREPARE_FOR_NEW_PRIMARY (  -
                FORMER_STANDBY_TYPE => 'LOGICAL',    -
                DBLINK => 'dblink_to_newprimary'); 

PURGE_SESSION Procedure

Identifies all archived redo log files that have been applied to the logical standby database and are no longer needed by SQL Apply. Once identified, you can issue operating system commands to delete some or all of the unnecessary archived redo log files.

Syntax

DBMS_LOGSTDBY.PURGE_SESSION;

Exceptions

Table 85-10 PURGE_SESSION Procedure Exceptions

Exception Description

ORA-01309

Invalid session


Usage Notes

Example

To identify and remove unnecessary files:

  1. Enter the following statement on the logical standby database:

    SQL> EXECUTE DBMS_LOGSTDBY.PURGE_SESSION;
    
  1. Query the DBA_LOGMNR_PURGED_LOG view to list the archived redo log files that can be removed:

    SQL> SELECT * FROM DBA_LOGMNR_PURGED_LOG;
    
    FILE_NAME
       ------------------------------------
       /boston/arc_dest/arc_1_40_509538672.log
       /boston/arc_dest/arc_1_41_509538672.log
       /boston/arc_dest/arc_1_42_509538672.log
       /boston/arc_dest/arc_1_43_509538672.log
       /boston/arc_dest/arc_1_44_509538672.log
       /boston/arc_dest/arc_1_45_509538672.log
       /boston/arc_dest/arc_1_46_509538672.log
       /boston/arc_dest/arc_1_47_509538672.log
    
  1. Use operating system-specific commands to delete archived redo log files from the file system.


REBUILD Procedure

This procedure is used if a database that has recently changed its role to a primary database following a failover operation fails to record relevant metadata (including the LogMiner dictionary) in the redo stream required for other logical standby databases.

Syntax

DBMS_LOGSTDBY.REBUILD;

Usage Notes

Examples

SQL> EXECUTE DBMS_LOGSTDBY.REBUILD;

SET_TABLESPACE Procedure

Moves metadata tables required by SQL Apply to the user-specified tablespace. By default, the metadata tables are created in the SYSAUX tablespace. SQL Apply cannot be running when you invoke this procedure.

Syntax

DBMS_LOGSTDBY.SET_TABLESPACE(
           NEW_TABLESPACE IN VARCHAR2)

Parameters

Table 85-11 SET_TABLE SPACE Procedure Parameters

Parameter Description

NEW_TABLESPACE

Name of the new tablespace where metadata tables will reside.


Exceptions

Table 85-12 SET_TABLESPACE Procedure Exceptions

Exception Description

ORA-16103

Logical Standby apply must be stopped to allow this operation

ORA-16236

Logical Standby metadata operation in progress


Examples

To move metadata tables to a new tablespace named LOGSTDBY_TBS, issue the following statement:

SQL> EXECUTE DBMS_LOGSTDBY.SET_TABLESPACE (new_tablespace => 'LOGSTDBY_TBS');

SKIP Procedure

The SKIP procedure can be used to define rules that will be used by SQL Apply to skip the application of certain changes to the logical standby database. For example, the SKIP procedure can be used to skip changes to a subset of tables in the logical standby database. It can also be used to specify DDL statements that should not be applied at the logical standby database or should be modified before they are applied in the logical standby database. One reason why a DDL statement may need to be modified is to accommodate a different directory structure on the logical standby database.

Syntax

DBMS_LOGSTDBY.SKIP (
     stmt                      IN VARCHAR2,
     schema_name               IN VARCHAR2 DEFAULT NULL,
     object_name               IN VARCHAR2 DEFAULT NULL,
     proc_name                 IN VARCHAR2 DEFAULT NULL,
     use_like                  IN BOOLEAN DEFAULT TRUE,
     esc                       IN CHAR1 DEFAULT NULL);

Parameters

Table 85-13 SKIP Procedure Parameters

Parameter Description

stmt

Either a keyword that identifies a set of SQL statements or a specific SQL statement. The use of keywords simplifies configuration since keywords, generally defined by the database object, identify all SQL statements that operate on the specified object. Table 85-14 shows a list of keywords and the equivalent SQL statements, either of which is a valid value for this parameter.

The keyword PL/SQL is used for the execution of Oracle-supplied packages which are supported for replication. See Oracle Data Guard Concepts and Administration for information about supported packages.

schema_name

The name of one or more schemas (wildcards are permitted) associated with the SQL statements identified by the stmt parameter. If not applicable, this value must be set to NULL.

object_name

The name of one or more objects (wildcards are permitted) associated with the SQL statements identified by the stmt. If not applicable, this value must be set to NULL.

proc_name

Name of a stored procedure to call when SQL Apply determines that a particular statement matches the filter defined by the stmt, schema_name, and object_name parameters. Specify the procedure in the following format:

'schema.package.procedure'

This procedure returns a value that directs SQL Apply to perform one of the following: execute the statement, skip the statement, or execute a replacement statement.

For DDLs, SQL Apply calls the stored procedure with the following call signature:

  • IN STATEMENT VARCHAR2 -- The SQL statement that matches the filter

  • IN STATEMENT_TYPE VARCHAR2 -- The stmt of the filter

  • IN SCHEMA VARCHAR2 -- The schema_name of the filter, if applicable

  • IN NAME VARCHAR2 -- The object_name of the filter, if applicable

  • IN XIDUSN NUMBER -- Transaction ID part 1

  • IN XIDSLT NUMBER -- Transaction ID part 2

  • IN XIDSQN NUMBER -- Transaction ID part 3

  • OUT SKIP_ACTION NUMBER -- Action to be taken by SQL Apply upon completion of this routine. Valid values are:

    SKIP_ACTION_APPLY -- Execute the statement

    SKIP_ACTION_SKIP -- Skip the statement

    SKIP_ACTION_ERROR -- Halt apply so the DBA can take appropriate steps (for example, take compensating action)

    SKIP_ACTION_REPLACE -- Execute the replacement statement supplied in the NEW_STATEMENT output parameter

For PL/SQL, SQL Apply calls the stored procedure with the following call signature:

  • IN STATEMENT VARCHAR2 -- The SQL statement that matches the filter

  • IN PACKAGE_SCHEMA VARCHAR2 -- The schema of the package being skipped (for example, SYS or XDB)

  • IN PACKAGE_NAME VARCHAR2 -- The name of the package being skipped (for example, DBMS_RLS)

  • IN PROCEDURE_NAME VARCHAR2 – The name of the procedure being skipped (for example, ADD_POLICY)

  • IN CURRENT_SCHEMA VARCHAR2 – The name of the current schema in which the PL/SQL was executed on the primary

  • IN XIDUSN NUMBER – Transaction ID part 1

  • IN XIDSLT NUMBER -- Transaction ID part 2

  • IN XIDSQN NUMBER -- Transaction ID part 3

  • IN EXIT_STATUS – 0 (Zero) if the PL/SQL succeeded on the primary, or 1

proc_name (cont.)

  • OUT SKIP_ACTION NUMBER -- Action to be taken by SQL Apply upon completion of this routine. Valid return values are:

    SKIP_ACTION_APPLY -- Execute the statement

    SKIP_ACTION_APPLY -- Execute the statement

    SKIP_ACTION_ERROR – Raise an error which halts apply so that the DBA can take appropriate steps

Note 1: SKIP_ACTION_REPLACE is not supported for PL/SQL.

Note 2: SQL Apply calls the skip handler when the procedure's exit is processed.

Note 3: The use_like parameter must be set to FALSE for PL/SQL since wildcarding PL/SQL is not supported.

The following example shows how to have a conditional skip rule on DBMS_RLS.DROP_POLICY:

Create or replace procedure sec_mgr.skip_drop_policy (
statement     in varchar2,
pkgown         in varchar2,
pkgname        in varchar2,
procnm         in varchar2,
cuser          in varchar2,
xidusn         in number,
xidslt         in number,
xidsqn         in number,
exstatus       in number,
skip_action    out number) Is
Begin
  If 0 = exstatus Then
    Insert Into sec_mgr.logit Values
      ('Success: '||pkgown||'.'||pkgname||'.'||procnm|| ' by '||cuser);
    
    If cuser != 'TESTSCHEMA' Then  
      skip_action := DBMS_LOGSTDBY.SKIP_ACTION_APPLY;
    Else
      skip_action := DBMS_LOGSTDBY.SKIP_ACTION_SKIP;
    End If;  
  End If;
End skip_drop_policy;

EXECUTE DBMS_LOGSTDBY.SKIP( -
     stmt => 'PL/SQL', -
     schema_name => 'SYS', -
     object_name => 'DBMS_RLS.DROP_POLICY', -
     proc_name => 'SEC_MGR.SKIP_DROP_POLICY' -
     use_like=> FALSE);

use_like

Allows pattern matching to isolate the tables that you want to skip on the logical standby database. The use_like parameter matches a portion of one character value to another by searching the first value for the pattern specified by the second, and calculates strings using characters as defined by the input character set. This parameter follows the same rules for pattern matching described in the Oracle Database SQL Language Reference.

esc

Identifies an escape character (such as the character "/") that you can use for pattern matching. If the escape character appears in the pattern before the character "%" or "_" then Oracle interprets this character literally in the pattern, rather than as a special pattern matching character. SeeOracle Database SQL Language Reference for more information about pattern matching.


Usage Notes

Skip Statement Options

Table 85-14 lists the supported values for the stmt parameter of the SKIP procedure. The left column of the table lists the keywords that may be used to identify the set of SQL statements to the right of the keyword. In addition, any of the SQL statements listed in the sys.audit_actions table (shown in the right column of Table 85-14) are also valid values. Note that keywords are generally defined by database object.

Table 85-14 Supported Values for the stmt Parameter

Keyword Associated SQL Statements

There is no keyword for this group of SQL statements.

GRANT
REVOKE
ANALYZE TABLE
ANALYZE INDEX
ANALYZE CLUSTER

CLUSTER

AUDIT CLUSTER
CREATE CLUSTER
DROP CLUSTER
TRUNCATE CLUSTER

CONTEXT

CREATE CONTEXT
DROP CONTEXT

DATABASE LINK

CREATE DATABASE LINK
CREATE PUBLIC DATABASE LINK
DROP DATABASE LINK
DROP PUBLIC DATABASE LINK

DIMENSION

ALTER DIMENSION
CREATE DIMENSION
DROP DIMENSION

DIRECTORYFoot 1 

CREATE DIRECTORY
DROP DIRECTORY

DML

Includes DML statements on a table (for example: INSERT, UPDATE, and DELETE)

INDEX

ALTER INDEX
CREATE INDEX
DROP INDEX

NON_SCHEMA_DDL

All DDL that does not pertain to a particular schema

Note: SCHEMA_NAME and OBJECT_NAME must be null

PL/SQLFoot 2 

Execute Oracle-supplied package.

PROCEDUREFoot 3 

ALTER FUNCTION
ALTER PACKAGE
ALTER PACKAGE BODY
ALTER PROCEDURE
CREATE FUNCTION
CREATE LIBRARY
CREATE PACKAGE
CREATE PACKAGE BODY
CREATE PROCEDURE
DROP FUNCTION
DROP LIBRARY
DROP PACKAGE
DROP PACKAGE BODY
DROP PROCEDURE

PROFILE

ALTER PROFILE
CREATE PROFILE
DROP PROFILE

ROLE

ALTER ROLE
CREATE ROLE
DROP ROLE
SET ROLE

ROLLBACK STATEMENT

ALTER ROLLBACK SEGMENT
CREATE ROLLBACK SEGMENT
DROP ROLLBACK SEGMENT

SCHEMA_DDL

All DDL statements that create, modify, or drop schema objects (for example: tables, indexes, and columns)

Note: SCHEMA_NAME and OBJECT_NAME must not be null

SEQUENCE

ALTER SEQUENCE
CREATE SEQUENCE
DROP SEQUENCE

SYNONYM

CREATE PUBLIC SYNONYM
CREATE SYNONYM
DROP PUBLIC SYNONYM
DROP SYNONYM

SYSTEM AUDIT

AUDIT SQL_statements
NOAUDIT SQL_statements

TABLE

CREATE TABLE
ALTER TABLE
DROP TABLE
TRUNCATE TABLE

TABLESPACE

CREATE TABLESPACE
DROP TABLESPACE
ALTER TABLESPACE

TRIGGER

ALTER TRIGGER
CREATE TRIGGER
DISABLE ALL TRIGGERS
DISABLE TRIGGER
DROP TRIGGER
ENABLE ALL TRIGGERS
ENABLE TRIGGER

TYPE

ALTER TYPE
ALTER TYPE BODY
CREATE TYPE
CREATE TYPE BODY
DROP TYPE
DROP TYPE BODY

USER

ALTER USER
CREATE USER
DROP USER

VIEW

CREATE VIEW
DROP VIEW

VIEW

CREATE VIEW
DROP VIEW

Footnote 1 All directory objects are owned by SYS, but for the purpose of filtering them with a skip directive the schema should be specified as '%'".

Footnote 2  See Oracle Data Guard Concepts and Administration for information about supported packages.

Footnote 3 Java schema objects (sources, classes, and resources) are considered the same as procedure for purposes of skipping (ignoring) SQL statements.

Exceptions

Table 85-15 DBMS_LOGSTDBY.SKIP Procedure Exceptions

Exception Description

ORA-01031

Insufficient privileges:

  • Procedure used INVOKER rights

  • Procedure needs DBA privileges

ORA-16103

Logical standby apply must be stopped to allow this operation.

ORA-16104

Invalid logical standby option requested.

ORA-16203

"Unable to interpret SKIP procedure return values."

Indicates that a SKIP procedure has either generated an exception or has returned ambiguous values. You can identify the offending procedure by examining the DBA_LOGSTDBY_EVENTS view.

ORA-16236

Logical standby metadata operation in progress.


Examples

Example 1   Skipping all DML and DDL changes made to a schema

The following example shows how to specify rules so that SQL Apply will skip both DDL and DML statements made to the HR schema.

SQL> EXECUTE DBMS_LOGSTDBY.SKIP(STMT => 'SCHEMA DDL', -
     schema_name => 'HR', -
     object_name => '%', -
     proc_name => null);
SQL> EXECUTE DBMS_LOGSTDBY.SKIP(STMT => 'DML', -
     schema_name => 'HR', -
     object_name => '%', -
     proc_name => null);
Example 2   Creating a procedure to handle different file system organization

For example, if the file system organization in the logical standby database is different than that in the primary database, you can write a SKIP procedure to handle DDL statements with file specifications transparently.The following procedure can handle DDL statements as long as you follow a specific naming convention for the file specification string.

  1. Create the SKIP procedure to handle tablespace DDL statements:

    CREATE OR REPLACE PROCEDURE sys.handle_tbs_ddl (
    
      old_stmt  IN  VARCHAR2,
      stmt_typ  IN  VARCHAR2,
      schema    IN  VARCHAR2,
      name      IN  VARCHAR2,
      xidusn    IN  NUMBER,
      xidslt    IN  NUMBER,
      xidsqn    IN  NUMBER,
      action    OUT NUMBER,
      new_stmt  OUT VARCHAR2
    ) AS
    BEGIN
     
    -- All primary file specification that contains a directory
    -- /usr/orcl/primary/dbs
    -- should go to /usr/orcl/stdby directory specification
     
     
      new_stmt = replace(old_stmt,
                         '/usr/orcl/primary/dbs',
                         '/usr/orcl/stdby');
     
      action := DBMS_LOGSTDBY.SKIP_ACTION_REPLACE;
     
    EXCEPTION
      WHEN OTHERS THEN
        action := DBMS_LOGSTDBY.SKIP_ACTION_ERROR;
        new_stmt := NULL;
    END handle_tbs_ddl;
    
  2. Register the SKIP procedure with SQL Apply:

    SQL> EXECUTE DBMS_LOGSTDBY.SKIP (stmt => 'TABLESPACE', -
                 proc_name => 'SYS.HANDLE_TBS_DDL');
    

SKIP_ERROR Procedure

Upon encountering an error, the logical standby database uses the criteria contained in this procedure to determine a course of action. The default action when a match is found is to skip the error and continue with applying changes. However, if a procedure is supplied, then SKIP_ERROR can take other actions depending on the situation. It can do nothing, which causes SQL Apply to stop, or it can change the error message text and stop SQL Apply, or it can actually skip the error.

Syntax

DBMS_LOGSTDBY.SKIP_ERROR (
     stmt                      IN VARCHAR2,
     schema_name               IN VARCHAR2 DEFAULT NULL,
     object_name               IN VARCHAR2 DEFAULT NULL,
     proc_name                 IN VARCHAR2 DEFAULT NULL,
     use_like                  IN BOOLEAN  DEFAULT NULL,
     esc                       IN CHAR1    DEFAULT NULL);

Parameters

Table 85-16 SKIP_ERROR Procedure Parameters

Parameter Description

stmt

Either a keyword that identifies a set of SQL statements or a specific SQL statement. The use of keywords simplifies configuration because keywords, generally defined by the database object, identify all SQL statements that operate on the specified object. Table 85-14 shows a list of keywords and the equivalent SQL statements, either of which is a valid value for this parameter.

schema_name

The name of one or more schemas (wildcards are permitted) associated with the SQL statements identified by the stmt parameter. If not applicable, this value must be set to NULL.

object_name

The name of one or more objects (wildcards are permitted) associated with the SQL statements identified by the stmt. If not applicable, this value must be set to NULL.

proc_name

Name of a stored procedure to call when SQL Apply encounters an error and determines a particular statement matches the filter defined by the stmt, schema_name, and object_name parameters. Specify the procedure in the following format:

'"schema"."package"."procedure"'

This procedure returns an error message that directs SQL Apply to perform one of the following actions:

  • Silently skip the error and continue with SQL Apply

  • Replace the error message that would have been created with a custom one, and stop SQL Apply

  • Do nothing, causing SQL Apply to stop and the original error message to be logged

SQL Apply calls the stored procedure with the following call signature:

  • IN STATEMENT VARCHAR(4000) -- The first 4K of the statement

  • IN STATEMENT_TYPE VARCHAR2 -- The stmt of the filter

  • IN SCHEMA VARCHAR2 -- The schema_name of the filter, if applicable

  • IN NAME VARCHAR2 -- The object_name of the filter, if applicable

  • IN XIDUSN NUMBER -- Transaction ID part 1

  • IN XIDSLT NUMBER -- Transaction ID part 2

  • IN XIDSQN NUMBER -- Transaction ID part 3

  • IN ERROR VARCHAR(4000) -- Text of the original error to be recorded

  • OUT NEW_ERROR VARCHAR(4000) -- Null or modified error text

use_like

Allows pattern matching to isolate the tables that you want to skip on the logical standby database. The use_like parameter matches a portion of one character value to another by searching the first value for the pattern specified by the second, and calculates strings using characters as defined by the input character set. This parameter follows the same rules for pattern matching described in the Oracle Database SQL Language Reference.

esc

Identifies an escape character (such as the characters "%" or "_") that you can use for pattern matching. If the escape character appears in the pattern before the character "%" or "_" then Oracle interprets this character literally in the pattern, rather than as a special pattern matching character. SeeOracle Database SQL Language Reference for more information about pattern matching.


Usage Notes

Exceptions

Table 85-17 SKIP_ERROR Procedure Exceptions

Exception Description

ORA-01031

Insufficient privileges:

  • Procedure used INVOKER rights

  • Procedure needs DBA privileges

ORA-16103

Logical Standby apply must be stopped to allow this operation

ORA-16104

invalid Logical Standby option requested

ORA-16236

Logical Standby metadata operation in progress


Example 1

The following example shows how to specify rules so that SQL Apply will skip any error raised from any GRANT DDL command.

SQL> EXECUTE DBMS_LOGSTDBY.SKIP_ERROR('GRANT') 

Example 2

To skip errors on GRANT statements on SYS or HR schemas, define a procedure handle_error_ddl and register it. In the following example, assume that handle_error_ddl is a free-standing procedure in the SYS schema.

  1. Create the error-handler procedure:

    CREATE OR REPLACE PROCEDURE sys.handle_error_ddl ( 
    old_stmt IN VARCHAR2, 
    stmt_type IN VARCHAR2, 
    schema IN VARCHAR2, 
    name IN VARCHAR2, 
    xidusn IN NUMBER, 
    xidslt IN NUMBER, 
    xidsqn IN NUMBER, 
    error IN VARCHAR2, 
    new_error OUT VARCHAR2 
    ) AS 
    BEGIN 
    -- Default to what we already have 
    new_error := error; 
    -- Ignore any GRANT errors on SYS or HR schemas 
    IF INSTR(UPPER(old_stmt),'GRANT') > 0 
    THEN 
    IF schema IS NULL 
    OR (schema IS NOT NULL AND 
    (UPPER(schema) = 'SYS' OR UPPER(schema) = 'HR' ) 
    THEN 
    new_error := NULL; 
    -- record the fact that we just skipped an error on 'SYS' or 'HR' schemas 
    -- code not shown here 
    END IF; 
    END IF; 
    END handle_error_ddl; 
    /
    
  2. Register the error handler with SQL Apply:

    SQL> EXECUTE DBMS_LOGSTDBY.SKIP_ERROR ( -
         statement => 'NON_SCHEMA_DDL', -
         schema_name => NULL, -
         object_name => NULL, -
         proc_name => 'SYS.HANDLE_ERROR_DDL');
    

SKIP_TRANSACTION Procedure

This procedure provides a way to skip (ignore) applying transactions to the logical standby database. You can skip specific transactions by specifying transaction identification information.

Syntax

DBMS_LOGSTDBY.SKIP_TRANSACTION (
     xidusn          IN NUMBER,
     xidslt          IN NUMBER,
     xidsqn          IN NUMBER);

Parameters

Table 85-18 SKIP_TRANSACTION Procedure Parameters

Parameter Description

XIDUSN NUMBER

Transaction ID undo segment number of the transaction being skipped

XIDSLT NUMBER

Transaction ID slot number of the transaction being skipped

XIDSQN NUMBER

Transaction ID sequence number of the transaction being skipped


Usage Notes

If SQL Apply stops due to a particular transaction (for example, a DDL transaction), you can specify that transaction ID and then continue to apply. You can call this procedure multiple times for as many transactions as you want SQL Apply to ignore.

CAUTION:

SKIP_TRANSACTION is an inherently dangerous operation. Do not invoke this procedure unless you have examined the transaction in question through the V$LOGMNR_CONTENTS view and have taken compensating actions at the logical standby database. SKIP_TRANSACTION is not the appropriate procedure to invoke to skip DML changes to a table.

To skip a DML failure, use a SKIP procedure, such as SKIP('DML','MySchema','MyFailed Table'). Using the SKIP_TRANSACTION procedure for DML transactions may skip changes for other tables, thus logically corrupting them.

Exceptions

Table 85-19 SKIP_TRANSACTION Procedure Exceptions

Exception Description

ORA-01031

Need DBA privileges

ORA-16103

Logical Standby apply must be stopped to allow this operation

ORA-16104

invalid Logical Standby option requested


Examples

To skip a DDL transaction with (XIDUSN, XIDSLT, XIDSQN) of (1.13.1726) you can register a rule as shown in the following example:

SQL> EXECUTE DBMS_LOGSTDBY.SKIP_TRANSACTION (- 
     XIDUSN => 1, XIDSLT => 13, XIDSQN => 1726);

UNSKIP Procedure

Use the UNSKIP procedure to delete rules specified earlier with the SKIP procedure. The parameters specified in the UNSKIP procedure must match exactly for it to delete an already-specified rule.

Syntax

DBMS_LOGSTDBY.UNSKIP (
     stmt                      IN VARCHAR2,
     schema_name               IN VARCHAR2 DEFAULT NULL,
     object_name               IN VARCHAR2 DEFUALT NULL);

Parameters

The parameter information for the UNSKIP procedure is the same as that described for the SKIP procedure. See Table 85-13 for complete parameter information.

Exceptions

Table 85-20 UNSKIP Procedure Exceptions

Exception Description

ORA-01031

need DBA privileges to execute this procedure

ORA-16103

Logical Standby apply must be stopped to allow this operation

ORA-16104

invalid Logical Standby option requested


Usage Notes

CAUTION:

If DML changes for a table have been skipped and not compensated for, you must follow the call to the UNSKIP procedure with a call to the INSTANTIATE_TABLE procedure to synchronize this table with those maintained by SQL Apply.


UNSKIP_ERROR Procedure

Use the UNSKIP_ERROR procedure to delete rules specified earlier with the SKIP_ERROR procedure. The parameters specified in the UNSKIP_ERROR procedure must match exactly for the procedure to delete an already-specified rule.

Syntax

DBMS_LOGSTDBY.UNSKIP_ERROR (
     stmt                      IN VARCHAR2,
     schema_name               IN VARCHAR2 DEFAULT NULL,
     object_name               IN VARCHAR2 DEFAULT NULL);

Parameters

The parameter information for the UNSKIP_ERROR procedure is the same as that described for the SKIP_ERROR procedure. See Table 85-16 for complete parameter information.

Exceptions

Table 85-21 UNSKIP_ERROR Procedure Exceptions

Exception Description

ORA-01031

Need DBA privileges

ORA-16103

Logical Standby apply must be stopped to allow this operation

ORA-16104

invalid Logical Standby option requested


Usage Notes

Example

To remove a handler that was previously registered with SQL Apply from getting called on encountering an error, you can issue the following statement:

DBMS_LOGSTDBY.UNSKIP_ERROR ( -
      statement => 'NON_SCHEMA_DDL', -
      schema_name => NULL, -
      object_name => NULL);

UNSKIP_TRANSACTION Procedure

Use the UNSKIP_TRANSACTION procedure to delete rules specified earlier with the SKIP_TRANSACTION procedure. The parameters specified in the UNSKIP_TRANSACTION procedure must match exactly for the procedure to delete an already-specified rule.

Syntax

DBMS_LOGSTDBY.UNSKIP_TRANSACTION (
     xidusn_p         IN NUMBER,
     xidslt_p         IN NUMBER,
     xidsqn_p         IN NUMBER);

Parameters

Table 85-22 UNSKIP_TRANSACTION Procedure Parameters

Parameter Description

XIDUSN

Transaction ID undo segment number of the transaction being skipped

XIDSLT

Transaction ID slot number of the transaction being skipped

XIDSQN

Transaction ID sequence number of the transaction being skipped


Exceptions

Table 85-23 UNSKIP_TRANSACTION Procedure Exceptions

Exception Description

ORA-01031

need DBA privileges to execute this procedure

ORA-16103

Logical Standby apply must be stopped to allow this operation

ORA-16104

invalid Logical Standby option requested


Usage Notes

Examples

To remove a rule that was originally specified to skip the application of a transaction with (XIDUSN, XIDSLT, XIDSQN) of (1.13.1726) issue the following statement:

SQL> DBMS_LOGSTDBY.UNSKIP_TRANSACTION (XIDUSN => 1, XIDSLT => 13, XIDSQN => 1726);