96
DBMS_STREAMS_ADM

The DBMS_STREAMS_ADM package, one of a set of Streams packages, provides administrative interfaces for adding and removing simple rules for capture, propagation, apply, and dequeue at the table, schema, and database level.

This chapter contains the following topics:

• Using DBMS_STREAMS_ADM
  • Overview
  • Rules
  • Users
• Summary of DBMS_STREAMS_ADM Subprograms

Using DBMS_STREAMS_ADM

• Overview
• Rules
• Users

Overview

The DBMS_STREAMS_ADM package, one of a set of Streams packages, provides administrative interfaces for adding and removing simple rules for capture, propagation, apply, and dequeue at the table, schema, and database level. These rules support logical change records (LCRs), which include row LCRs and data definition language (DDL) LCRs. This package also contains subprograms for creating message rules for specific message types. This package also contains subprograms for creating queues and for managing Streams metadata, such as data dictionary information.

If you require more sophisticated rules, then you can use the DBMS_RULE_ADM package.

Rules

Streams clients include capture processes, propagations, apply processes, and messaging clients. Some of the procedures in the DBMS_STREAMS_ADM package add rules to the rule sets of Streams clients. The rules may pertain to changes in the redo log, to logical change records (LCRs), or to user messages.

An LCR represents either a row change that results from a data manipulation language (DML) change or a data definition language (DDL) change. An LCR that represents a row change is a row LCR, and an LCR that represents a DDL change is a DDL LCR. LCRs either may represent changes in the redo record that were captured by a capture process, or they may represent changes created by a user or application. User messages are custom messages that are based on a user-defined types and created by users or applications.

For all of the procedures except the ones that create subset rules, you use the inclusion_rule parameter to specify the type of rule set (either positive or negative) for the created rules. If the Streams client does not have a rule set of the specified type, then a rule set is created automatically, and the rules are added to the rule set. Other rules in an existing rule set for the Streams client are not affected. Additional rules can be added to a rule set using either the DBMS_STREAMS_ADM package or the DBMS_RULE_ADM package. If a Streams client has both a positive and a negative rule set, then the negative rule set is always evaluated first.

The following sections describe each type of rule in detail:

• Capture Process Rules for Changes in the Redo Log
• Propagation Rules for LCRs
• Propagation Rules for User Messages
• Apply Process Rules for LCRs
• Apply Process Rules for User Messages
• Messaging Client Rules for LCRs
• Messaging Client Rules for User Messages

  See Also: Oracle Streams Concepts and Administration for more information about how rules are used in Streams

Capture Process Rules for Changes in the Redo Log

The following procedures add rules to a rule set of a capture process when you specify capture for the streams_type parameter:

• The ADD_GLOBAL_RULES procedure adds rules whose rule condition evaluates to TRUE for all changes made to a source database. See "ADD_GLOBAL_RULES Procedures".
• The ADD_SCHEMA_RULES procedure adds rules whose rule condition evaluates to TRUE for changes made to a specified schema. See "ADD_SCHEMA_RULES Procedures".
• The ADD_SUBSET_RULES procedure adds rules whose rule condition evaluates to TRUE for DML changes made to a subset of rows in a specified table. See "ADD_SUBSET_RULES Procedures".
• The ADD_TABLE_RULES procedure adds rules whose rule condition evaluates to TRUE for changes made to a specified table. See "ADD_TABLE_RULES Procedures".

If one of these procedures adds rules to the positive rule set for a capture process, then the capture process captures row changes resulting from DML changes, or DDL changes, or both from a source database and enqueues these changes into the specified queue. If one of these procedures adds rules to the negative rule set for a capture process, then the capture process discards row changes, or DDL changes, or both from a source database.

A capture process can capture changes locally at a source database or remotely at a downstream database. Therefore, for capture process rules, you should execute this procedure either at the source database or at a downstream database.

If the capture process is a local capture process, or if the capture process is a downstream capture process that uses a database link to the source database, then these procedures automatically prepare the appropriate database objects for instantiation:

• ADD_GLOBAL_RULES invokes the PREPARE_GLOBAL_INSTANTIATION procedure in the DBMS_CAPTURE_ADM package at the source database.
• ADD_SCHEMA_RULES invokes the PREPARE_SCHEMA_INSTANTIATION procedure in the DBMS_CAPTURE_ADM package at the source database.
• ADD_SUBSET_RULES and ADD_TABLE_RULES invoke the PREPARE_TABLE_INSTANTIATION procedure in the DBMS_CAPTURE_ADM package at the source database.

If the capture process is a downstream capture process that does not use a database link to the source database, then you must prepare the appropriate objects for instantiation manually at the source database.

If one of these procedures is executed at a downstream database, then you specify the source database using the source_database parameter, and the specified capture process must exist. The procedure cannot create a capture process if it is run at a downstream database. You can create a capture process at a downstream database using the CREATE_CAPTURE procedure in the DBMS_CAPTURE_ADM package.

Propagation Rules for LCRs

The following procedures add propagation rules to a rule set of a propagation:

• The ADD_GLOBAL_PROPAGATION_RULES procedure adds rules whose rule condition evaluates to TRUE for all LCRs in a source queue. See "ADD_GLOBAL_PROPAGATION_RULES Procedures".
• The ADD_SCHEMA_PROPAGATION_RULES procedure adds rules whose rule condition evaluates to TRUE for LCRs in a source queue containing changes made to a specified schema. See "ADD_SCHEMA_PROPAGATION_RULES Procedures".
• The ADD_SUBSET_PROPAGATION_RULES procedure adds rules whose rule condition evaluates to TRUE for row LCRs in a source queue containing the results of DML changes made to a subset of rows in a specified table. See "ADD_SUBSET_PROPAGATION_RULES Procedures".
• The ADD_TABLE_PROPAGATION_RULES procedure adds rules whose rule condition evaluates to TRUE for LCRs in a source queue containing changes made to a specified table. See "ADD_TABLE_PROPAGATION_RULES Procedure".

If one of these procedures adds rules to the positive rule set for the propagation, then the rules specify that the propagation propagates LCRs in a source queue to a destination queue. If one of these procedures adds rules to the negative rule set for the propagation, then the rules specify that the propagation discards LCRs in a source queue. When you create rules with one of these procedures, and you specify a value for the source_databse parameter, then the rules include conditions for the specified source database.

Propagation Rules for User Messages

The ADD_MESSAGE_PROPAGATION_RULE procedure adds a message rule to a rule set of a propagation. If this procedure adds a rule to the positive rule set for the propagation, then the rule specifies that the propagation propagates the user-enqueued messages of a specific message type that evaluate to TRUE for the rule condition in a source queue to a destination queue. If this procedure adds a rule to the negative rule set for the propagation, then the rule specifies that the propagation discards the user-enqueued messages of a specific message type that evaluate to TRUE for the rule condition in a source queue. This procedure generates a rule name for the rule.

Apply Process Rules for LCRs

The following procedures add rules to a rule set of an apply process when you specify apply for the streams_type parameter:

• The ADD_GLOBAL_RULES procedure adds rules whose rule condition evaluates to TRUE for all LCRs in the apply process queue. See "ADD_GLOBAL_RULES Procedures".
• The ADD_SCHEMA_RULES procedure adds rules whose rule condition evaluates to TRUE for LCRs in the apply process queue containing changes made to a specified schema. See "ADD_SCHEMA_RULES Procedures".
• The ADD_SUBSET_RULES procedure adds rules whose rule condition evaluates to TRUE for row LCRs in the apply process queue containing the results of DML changes made to a subset of rows in a specified table. See "ADD_SUBSET_RULES Procedures".
• The ADD_TABLE_RULES procedure adds rules whose rule condition evaluates to TRUE for LCRs in the apply process queue containing changes made to a specified table. See "ADD_TABLE_RULES Procedures".

If one of these procedures adds rules to the positive rule set for the apply process, then the rules specify that the apply process applies LCRs in its queue. If one of these procedures adds rules to the negative rule set for the apply process, then the rules specify that the apply process discards LCRs in its queue. For apply process rules, you should execute these procedures at the destination database.

An apply process can apply captured LCRs from only one source database. If one of these procedures creates an apply process, then specify the source database for the apply process using the source_database parameter. If the source_database parameter is NULL, and one of these procedures creates an apply process, then the source database name of the first LCR received by the apply process is used for the source database.

The rules in the apply process rule sets determine which events are dequeued by the apply process. When you create rules with one of these procedures, and you specify a value for the source_databse parameter, then the rules include conditions for the specified source database. If the apply process dequeues an LCR with a source database that is different than the source database for the apply process, then an error is raised. In addition, when adding rules to an existing apply process, the database specified in the source_database parameter cannot be different than the source database for the apply process. You can determine the source database for an apply process by querying the DBA_APPLY_PROGRESS data dictionary view.

Changes applied by an apply process created by one of these procedures generate tags in the redo log at the destination database with a value of '00' (double zero). You can use the ALTER_APPLY procedure in the DBMS_APPLY_ADM package to alter the tag value after the apply process is created, if necessary.

An apply process created by one of these procedures can apply events only at the local database and can apply only captured events. To create an apply process that applies events at a remote database or an apply process that applies user-enqueued events, use the CREATE_APPLY procedure in the DBMS_APPLY_ADM package.

You also can use the DBMS_APPLY_ADM.CREATE_APPLY procedure to specify nondefault values for the apply_captured, apply_user, apply_database_link, and apply_tag parameters when you run that procedure. You can use one of the procedures in the DBMS_STREAMS_ADM package to add rules to a rule set used by the apply process after you create it.

Apply Process Rules for User Messages

The ADD_MESSAGE_RULE procedure adds a message rule to a rule set of an apply process when you specify apply for the streams_type parameter. For an apply process rule, you should execute this procedure at the destination database.

If this procedure adds a rule to the positive rule set for an apply process, then the apply process dequeues user-enqueued messages of a specific message type that satisfy the apply process rule and sends these messages to its message handler. If no message handler is specified for the apply process, then use the ALTER_APPLY procedure in the DBMS_APPLY_ADM package to set the message handler. If this procedure adds a rule to the negative rule set for an apply process, then the apply process discards user-enqueued messages of a specific message type that satisfy the apply process rule.

Messaging Client Rules for LCRs

The following procedures add rules to a rule set of a messaging client when you specify dequeue for the streams_type parameter:

• The ADD_GLOBAL_RULES procedure adds rules whose rule condition evaluates to TRUE for all LCRs in the messaging client queue. See "ADD_GLOBAL_RULES Procedures".
• The ADD_SCHEMA_RULES procedure adds rules whose rule condition evaluates to TRUE for LCRs in the messaging client queue containing changes made to a specified schema. See "ADD_SCHEMA_RULES Procedures".
• The ADD_SUBSET_RULES procedure adds rules whose rule condition evaluates to TRUE for row LCRs in the messaging client queue containing the results of DML changes made to a subset of rows in a specified table. See "ADD_SUBSET_RULES Procedures".
• The ADD_TABLE_RULES procedure adds rules whose rule condition evaluates to TRUE for LCRs in the messaging client queue containing changes made to a specified table. See "ADD_TABLE_RULES Procedures".

If one of these procedures adds rules to the positive rule set for a messaging client, then the messaging client can dequeue user-enqueued row LCRs, or DDL LCRs, or both that originated at the source database matching the source_database parameter. If one of these procedures adds rules to the negative rule set for a messaging client, then the messaging client discards user-enqueued row LCRs, or DDL LCRs, or both that originated at the source database matching the source_database parameter. You should execute these procedures at the database where you want to dequeue the events with the messaging client.

Messaging Client Rules for User Messages

The ADD_MESSAGE_RULE procedure adds a message rule to a rule set of a messaging client when you specify dequeue for the streams_type parameter. You should execute this procedure at the database that will dequeue messages.

If this procedure adds a rule to the positive rule set for a messaging client, then the messaging client dequeues user-enqueued messages of a specific message type that satisfy the message rule. If this procedure adds a rule to the negative rule set for a messaging client, then the messaging client discards user-enqueued messages of a specific message type that satisfy the message rule.

Users

A user is associated with each Streams client. The following sections describe these users.

Capture User

The following procedures can create a capture process:

• ADD_GLOBAL_RULES Procedures
• ADD_SCHEMA_RULES Procedures
• ADD_SUBSET_RULES Procedures
• ADD_TABLE_RULES Procedures

If one of these procedures creates a capture process, then it configures the current user as the capture_user. This user captures changes that satisfy the capture process rule sets. This user must have the necessary privileges to capture changes. The 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.

Propagation User

The following procedures can create a propagation:

• ADD_GLOBAL_PROPAGATION_RULES Procedures
• ADD_MESSAGE_PROPAGATION_RULE Procedures
• ADD_SCHEMA_PROPAGATION_RULES Procedures
• ADD_SUBSET_PROPAGATION_RULES Procedures
• ADD_TABLE_PROPAGATION_RULES Procedure

When a propagation is created, a propagation job is created also if one does not exist for the database link used by the propagation. If a propagation job is created when one of these procedures is run, then the user who runs the procedure owns the propagation job.

Apply User

The following procedures can create an apply process:

• ADD_GLOBAL_RULES Procedures
• ADD_MESSAGE_RULE Procedures
• ADD_SCHEMA_RULES Procedures
• ADD_SUBSET_RULES Procedures
• ADD_TABLE_RULES Procedures

If one of these procedures creates an apply process, then it configures the current user as the apply_user. This user applies changes that satisfy the apply process rule sets and runs user-defined apply handlers. This user must have the necessary privileges to apply changes. The procedure grants the apply user dequeue privilege on the queue used by the apply process and configures the user as a secure queue user of the queue.

Messaging Client User

The following procedures can create a messaging client:

• ADD_GLOBAL_RULES Procedures
• ADD_MESSAGE_RULE Procedures
• ADD_SCHEMA_RULES Procedures
• ADD_SUBSET_RULES Procedures
• ADD_TABLE_RULES Procedures

If one of these procedures creates a messaging client, then the user who runs this procedure is granted the privileges to dequeue from the queue using the messaging client. The procedure configures this user as a secure queue user of the queue, and only this user can use the messaging client.

Summary of DBMS_STREAMS_ADM Subprograms

Table 96-1  DBMS_STREAMS_ADM Package Subprograms

ADD_GLOBAL_PROPAGATION_RULES Procedures

These procedures either add global rules to the positive rule set for a propagation, or add global rules to the negative rule set for a propagation, and create the specified propagation if it does not exist.

Syntax

DBMS_STREAMS_ADM.ADD_GLOBAL_PROPAGATION_RULES(
   streams_name            IN   VARCHAR2  DEFAULT NULL,
   source_queue_name       IN   VARCHAR2,
   destination_queue_name  IN   VARCHAR2,
   include_dml             IN   BOOLEAN   DEFAULT true,
   include_ddl             IN   BOOLEAN   DEFAULT false,
   include_tagged_lcr      IN   BOOLEAN   DEFAULT false,
   source_database         IN   VARCHAR2  DEFAULT NULL,
   dml_rule_name           OUT  VARCHAR2,
   ddl_rule_name           OUT  VARCHAR2,
   inclusion_rule          IN   BOOLEAN   DEFAULT true,
   and_condition           IN   VARCHAR2  DEFAULT NULL);

Parameters

Table 96-2  ADD_GLOBAL_PROPAGATION_RULES Procedure Parameters

(system_condition) AND (and_condition)

:lcr.get_tag() = HEXTORAW(''02'')

Usage Notes

This procedure creates DML and DDL rules automatically based on include_dml and include_ddl parameter values, respectively. A system-generated rule name is the database name with a sequence number appended to it. The sequence number is used to avoid naming conflicts. If the database name plus the sequence number is too long, then the database name is truncated. The overloaded ADD_GLOBAL_PROPAGATION_RULES procedure generates the rule names for DML and DDL changes. A propagation uses the rules created for filtering.

If no propagation job exists for the database link specified in the destination_queue_name parameter when this procedure is run, then a propagation job is created for use by the propagation. If a propagation job already exists for the specified database link, then the propagation uses the existing propagation job.

This procedure also configures propagation using the current user, and establish a default propagation schedule. Only one propagation is allowed between the source queue and destination queue.

Examples

The following is an example of a global rule condition that may be created for DML changes:

:dml.get_source_database_name() = 'DBS1.NET' AND :dml.is_null_tag() = 'Y'

ADD_GLOBAL_RULES Procedures

These procedures add rules to a rule set of one of the following types of Streams clients:

• Capture process rules for capturing changes to an entire database when the streams_type parameter is set to capture. See "Capture Process Rules for Changes in the Redo Log" for more information about these rules.
• Apply process rules for applying all logical change records (LCRs) in a queue when the streams_type parameter is set to apply. The rules may specify that the LCRs must be from a particular source database. See "Apply Process Rules for LCRs" for more information about these rules.
• Messaging client rules for dequeuing all user-enqueued LCRs from a queue when the streams_type parameter is set to dequeue. The rules may specify that the LCRs must be from a particular source database. See "Messaging Client Rules for LCRs" for more information about these rules.

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

Syntax

DBMS_STREAMS_ADM.ADD_GLOBAL_RULES(
   streams_type        IN   VARCHAR2,
   streams_name        IN   VARCHAR2  DEFAULT NULL,
   queue_name          IN   VARCHAR2  DEFAULT 'streams_queue',
   include_dml         IN   BOOLEAN   DEFAULT true,
   include_ddl         IN   BOOLEAN   DEFAULT false,
   include_tagged_lcr  IN   BOOLEAN   DEFAULT false,
   source_database     IN   VARCHAR2  DEFAULT NULL,
   dml_rule_name       OUT  VARCHAR2,
   ddl_rule_name       OUT  VARCHAR2,
   inclusion_rule      IN   BOOLEAN   DEFAULT true,
   and_condition       IN   VARCHAR2  DEFAULT NULL);

Parameters

Table 96-3  ADD_GLOBAL_RULES Procedure Parameters

(system_condition) AND (and_condition)

:lcr.get_tag() = HEXTORAW(''02'')

Usage Notes

This procedure creates the specified capture process, apply process, or messaging client if it does not exist.

This procedure creates DML and DDL rules automatically based on include_dml and include_ddl parameter values, respectively. A system-generated rule name is the database name with a sequence number appended to it. The sequence number is used to avoid naming conflicts. If the database name plus the sequence number is too long, then the database name is truncated. The overloaded ADD_GLOBAL_RULES procedure generates the rule names for DML and DDL changes. A capture process, apply process, or messaging client uses the rules created for filtering.

Examples

The following is an example of a global rule condition that may be created for DML changes:

:dml.get_source_database_name() = 'DBS1.NET' AND :dml.is_null_tag() = 'Y'

ADD_MESSAGE_PROPAGATION_RULE Procedures

These procedures add a message rule to the positive rule set for a propagation, or add a message rule to the negative rule set for a propagation, and create the specified propagation if it does not exist.

Syntax

DBMS_STREAMS_ADM.ADD_MESSAGE_PROPAGATION_RULE(
   message_type            IN   VARCHAR2,    
   rule_condition          IN   VARCHAR2,    
   streams_name            IN   VARCHAR2  DEFAULT NULL,    
   source_queue_name       IN   VARCHAR2,    
   destination_queue_name  IN   VARCHAR2,    
   inclusion_rule          IN   BOOLEAN   DEFAULT true,
   rule_name               OUT  VARCHAR2);

Parameters

Table 96-4  ADD_MESSAGE_PROPAGATION_RULE Procedure Parameters

:msg

Usage Notes

When you use this procedure to create a rule set for a message rule, the new rule set does not have an evaluation context. If no evaluation context exists for the specified message type, then this procedure creates a new evaluation context and associates it with the new rule. The evaluation context also has a system-generated name. If you create new rules that use an existing message type, then the new rules use the existing evaluation context for the message type.

If no propagation job exists for the database link specified in the destination_queue_name parameter when this procedure is run, then a propagation job is created for use by the propagation. If a propagation job already exists for the specified database link, then the propagation uses the existing propagation job.

This procedure also configures propagation using the current user, and establishes a default propagation schedule. Only one propagation is allowed between the source queue and destination queue.

Examples

Suppose the message type is usr_msg, and that this type has the following attributes: source_dbname, owner, name, and message. Given this type, the following rule condition may be specified:

':msg.source_dbname = ''DBS1.NET'' AND ' || ':msg.owner = ''HR'' AND  ' || 
':msg.name = ''EMPLOYEES'''

This rule condition evaluates to TRUE if a user-enqueued message of type usr_msg has dbs1.net for its source_dbname attribute, hr for its owner attribute, and employees for its name attribute.

ADD_MESSAGE_RULE Procedures

These procedures a message rule to a rule set of one of the following types of Streams clients:

• Apply process rule for dequeuing user-enqueued messages of a specific message type from a queue when the streams_type parameter is set to apply. See "Apply Process Rules for User Messages" for more information about such rules.
• Messaging client rule dequeuing user-enqueued messages of a specific message type from a queue when the streams_type parameter is set to dequeue. See "Messaging Client Rules for User Messages" for more information about such rules.

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

Syntax

DBMS_STREAMS_ADM.ADD_MESSAGE_RULE(
   message_type    IN   VARCHAR2,    
   rule_condition  IN   VARCHAR2,    
   streams_type    IN   VARCHAR2,
   streams_name    IN   VARCHAR2  DEFAULT NULL,    
   queue_name      IN   VARCHAR2  DEFAULT 'streams_queue',    
   inclusion_rule  IN   BOOLEAN   DEFAULT true,
   rule_name       OUT  VARCHAR2);

Parameters

Table 96-5  ADD_MESSAGE_RULE Procedure Parameters

:msg

Usage Notes

If an apply process rule is added, then this procedure creates the apply process if it does not exist. An apply process created by this procedure can apply only user-enqueued messages, and dequeued messages are sent to the message handler for the apply process. If a messaging client rule is added, then this procedure creates a messaging client if it does not exist.

When you use this procedure to create a rule set for a message rule, the new rule set does not have an evaluation context. If no evaluation context exists for the specified message type, then this procedure creates a new evaluation context and associates it with the new rule. The evaluation context also has a system-generated name. If you create new rules that use an existing message type, then the new rules use the existing evaluation context for the message type.

Examples

You specify the condition for this rule using the rule_condition parameter. For example, suppose the message type is usr_msg, and that this type has the following attributes: source_dbname, owner, name, and message. Given this type, the following rule condition may be specified:

':msg.source_dbname = ''DBS1.NET'' AND ' || ':msg.owner = ''HR'' AND  ' || 
':msg.name = ''EMPLOYEES'''

ADD_SCHEMA_PROPAGATION_RULES Procedures

These procedures either add schema rules to the positive rule set for a propagation, or add schema rules to the negative rule set for a propagation, and create the specified propagation if it does not exist.

Syntax

DBMS_STREAMS_ADM.ADD_SCHEMA_PROPAGATION_RULES(
   schema_name             IN   VARCHAR2,
   streams_name            IN   VARCHAR2 DEFAULT NULL,
   source_queue_name       IN   VARCHAR2,
   destination_queue_name  IN   VARCHAR2,
   include_dml             IN   BOOLEAN  DEFAULT true,
   include_ddl             IN   BOOLEAN  DEFAULT false,
   include_tagged_lcr      IN   BOOLEAN  DEFAULT false,
   source_database         IN   VARCHAR2 DEFAULT NULL,
   dml_rule_name           OUT  VARCHAR2,
   ddl_rule_name           OUT  VARCHAR2,
   inclusion_rule          IN   BOOLEAN   DEFAULT true,
   and_condition           IN   VARCHAR2  DEFAULT NULL);

Parameters

Table 96-6  ADD_SCHEMA_PROPAGATION_RULES Procedure Parameters

(system_condition) AND (and_condition)

:lcr.get_tag() = HEXTORAW(''02'')

Usage Notes

This procedure creates DML and DDL rules automatically based on include_dml and include_ddl parameter values, respectively. A system-generated rule name is the schema name with a sequence number appended to it. The sequence number is used to avoid naming conflicts. If the schema name plus the sequence number is too long, then the schema name is truncated. For the overloaded ADD_SCHEMA_PROPAGATION_RULES procedure this generates the rule names for DML and DDL changes. A propagation uses the rules created for filtering.

If no propagation job exists for the database link specified in the destination_queue_name parameter when this procedure is run, then a propagation job is created for use by the propagation. If a propagation job already exists for the specified database link, then the propagation uses the existing propagation job.

This procedure also configures propagation using the current user, and establishes a default propagation schedule. Only one propagation is allowed between the source queue and the destination queue.

Examples

The following is an example of a schema rule condition that may be created for DML changes:

:dml.get_object_owner() = 'HR' AND :dml.is_null_tag() = 'Y'
AND :dml.get_source_database_name() = 'DBS1.NET'

ADD_SCHEMA_RULES Procedures

These procedures add rules to a rule set of one of the following types of Streams clients:

• Capture process rules for capturing changes to a specified schema when the streams_type parameter is set to capture. See "Capture Process Rules for Changes in the Redo Log" for more information about these rules.
• Apply process rules for applying logical change records (LCRs) in a queue that contain changes to a specified schema when the streams_type parameter is set to apply. The rules may specify that the LCRs must be from a particular source database. See "Apply Process Rules for LCRs" for more information about these rules.
• Messaging client rules for dequeuing user-enqueued LCRs from a queue that contain changes to a specified schema when the streams_type parameter is set to dequeue. The rules may specify that the LCRs must be from a particular source database. See "Messaging Client Rules for LCRs" for more information about these rules.

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

Syntax

DBMS_STREAMS_ADM.ADD_SCHEMA_RULES(
   schema_name         IN   VARCHAR2,
   streams_type        IN   VARCHAR2,
   streams_name        IN   VARCHAR2  DEFAULT NULL,
   queue_name          IN   VARCHAR2  DEFAULT 'streams_queue',
   include_dml         IN   BOOLEAN   DEFAULT true,
   include_ddl         IN   BOOLEAN   DEFAULT false,
   include_tagged_lcr  IN   BOOLEAN   DEFAULT false,
   source_database     IN   VARCHAR2  DEFAULT NULL,
   dml_rule_name       OUT  VARCHAR2,
   ddl_rule_name       OUT  VARCHAR2,
   inclusion_rule      IN   BOOLEAN   DEFAULT true,
   and_condition       IN   VARCHAR2  DEFAULT NULL);

Parameters

Table 96-7  ADD_SCHEMA_RULES Procedure Parameters

(system_condition) AND (and_condition)

:lcr.get_tag() = HEXTORAW(''02'')

Usage Notes

This procedure creates the specified capture process, apply process, or messaging client if it does not exist.

This procedure creates DML and DDL rules automatically based on include_dml and include_ddl parameter values, respectively. A system-generated rule name is the schema name with a sequence number appended to it. The sequence number is used to avoid naming conflicts. If the schema name plus the sequence number is too long, then the schema name is truncated. The overloaded ADD_SCHEMA_RULES procedure generates the rule names for DML and DDL changes. A capture process, apply process, or messaging client uses the rules created for filtering.

Examples

The following is an example of a schema rule condition that may be created for DML changes:

:dml.get_object_owner() = 'HR' AND :dml.is_null_tag() = 'Y'

ADD_SUBSET_PROPAGATION_RULES Procedures

These procedures add propagation rules that propagate the logical change records (LCRs) related to a subset of the rows in the specified table in a source queue to a destination queue, and creates the specified propagation if it does not exist. They also configure propagation using the current user and establishes a default propagation schedule. The procedures enables propagation of LCRs for the specified table, subject to filtering conditions.

Syntax

DBMS_STREAMS_ADM.ADD_SUBSET_PROPAGATION_RULES(
   table_name               IN   VARCHAR2,
   dml_condition            IN   VARCHAR2,
   streams_name             IN   VARCHAR2 DEFAULT NULL,
   source_queue_name        IN   VARCHAR2,
   destination_queue_name   IN   VARCHAR2,
   include_tagged_lcr       IN   BOOLEAN  DEFAULT false,
   source_database          IN   VARCHAR2 DEFAULT NULL,
   insert_rule_name         OUT  VARCHAR2,
   update_rule_name         OUT  VARCHAR2,
   delete_rule_name         OUT  VARCHAR2);

Parameters

Table 96-8  ADD_SUBSET_PROPAGATION_RULES Procedure Parameters

Usage Notes

Only one propagation is allowed between the source queue and the destination queue.

Running this procedure generates three rules for the specified propagation: one for INSERT statements, one for UPDATE statements, and one for DELETE statements. For INSERT and DELETE statements, only row LCRs that satisfy the condition specified for the dml_condition parameter are propagated. For UPDATE statements, the following variations are possible:

• If both the new and old values in a row LCR satisfy the specified dml_condition, then the row LCR is propagated without any changes.
• If neither the new or old values in a row LCR satisfy the specified dml_condition, then the row LCR is not propagated.
• If the old values for a row LCR satisfy the specified dml_condition, but the new values do not, then the update row LCR is converted into a delete row LCR.
• If the new values for a row LCR satisfy the specified dml_condition, but the old values do not, then the update row LCR is converted to an insert row LCR.

When an update is converted into an insert or a delete, it is called row migration.

A propagation uses the rules created for filtering. If the propagation does not have a positive rule set, then a positive rule set is created automatically, and the rules for propagating changes to the table are added to the positive rule set. A subset rule can be added to positive rule set only, not to a negative rule set. Other rules in an existing positive rule set for the propagation are not affected. Additional rules can be added using either the DBMS_STREAMS_ADM package or the DBMS_RULE_ADM package.

Rules for INSERT, UPDATE, and DELETE statements are created automatically when you run this procedure, and these rules are given a system-generated rule name. The system-generated rule name is the table name with a sequence number appended to it. The sequence number is used to avoid naming conflicts. If the table name plus the sequence number is too long, then the table name is truncated. The ADD_SUBSET_RULES procedure is overloaded, and the system-generated rule names for INSERT, UPDATE, and DELETE statements are returned.

When you create propagation subset rules for a table, you should create an unconditional supplemental log group at the source database with all the columns in the table. Supplemental logging is required if an update must be converted to an insert. The propagation rule must have all the column values to be able to perform this conversion correctly.

For a propagation to work properly, the owner of the source queue must have the necessary privileges to propagate events.

If no propagation job exists for the database link specified in the destination_queue_name parameter when this procedure is run, then a propagation job is created for use by the propagation. If a propagation job already exists for the specified database link, then the propagation uses the existing propagation job.

Examples

The following is an example of a rule condition that may be created for filtering a row LCR containing an update operation when the dml_condition is region_id = 2 and the table_name is hr.regions:

:dml.get_object_owner() = 'HR' AND :dml.get_object_name() = 'REGIONS' AND 
:dml.is_null_tag() = 'Y' AND :dml.get_command_type() = 'UPDATE' AND (:dml.get_
value('NEW','"REGION_ID"') IS NOT NULL) AND (:dml.get_value('OLD','"REGION_ID"') 
IS NOT NULL) AND (:dml.get_value('OLD','"REGION_ID"').AccessNumber()=2) AND 
(:dml.get_value('NEW','"REGION_ID"').AccessNumber()=2)

ADD_SUBSET_RULES Procedures

These procedures add rules to a rule set of one of the following types of Streams clients:

• Capture process rules for capturing changes to a subset of rows in a specified table when the streams_type parameter is set to capture. See "Capture Process Rules for Changes in the Redo Log" for more information about these rules.
• Apply process rules for applying logical change records (LCRs) in a queue that contain changes to a subset of rows in a specified table when the streams_type parameter is set to apply. The rules may specify that the LCRs must be from a particular source database. See "Apply Process Rules for LCRs" for more information about these rules.
• Messaging client rules for dequeuing user-enqueued LCRs from a queue that contain changes to a subset of rows in a specified table when the streams_type parameter is set to dequeue. The rules may specify that the LCRs must be from a particular source database. See "Messaging Client Rules for LCRs" for more information about these rules.

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

Syntax

DBMS_STREAMS_ADM.ADD_SUBSET_RULES(
   table_name          IN   VARCHAR2,
   dml_condition       IN   VARCHAR2,
   streams_type        IN   VARCHAR2 DEFAULT 'apply',
   streams_name        IN   VARCHAR2 DEFAULT NULL,
   queue_name          IN   VARCHAR2 DEFAULT 'streams_queue',
   include_tagged_lcr  IN   BOOLEAN  DEFAULT false,
   source_database     IN   VARCHAR2 DEFAULT NULL,
   insert_rule_name    OUT  VARCHAR2,
   update_rule_name    OUT  VARCHAR2,
   delete_rule_name    OUT  VARCHAR2);

Parameters

Table 96-9  ADD_SUBSET_RULES Procedure Parameters

Usage Notes

This procedure creates the specified capture process, apply process, or messaging client if it does not exist.

Running this procedure generates three rules for the specified capture process, apply process, or messaging client: one for INSERT statements, one for UPDATE statements, and one for DELETE statements. For INSERT and DELETE statements, only DML changes that satisfy the condition specified for the dml_condition parameter are captured, applied, or dequeued. For UPDATE statements, the following variations are possible:

• If both the new and old values in a DML change satisfy the specified dml_condition, then the DML change is captured, applied, or dequeued without any changes.
• If neither the new or old values in a DML change satisfy the specified dml_condition, then the DML change is not captured, applied, or dequeued.
• If the old values for a DML change satisfy the specified dml_condition, but the new values do not, then the DML change is converted into a delete.
• If the new values for a DML change satisfy the specified dml_condition, but the old values do not, then the DML change is converted to an insert.

When an update is converted into an insert or a delete, it is called row migration.

A capture process, apply process, or messaging client uses the rules created for filtering. If the Streams client does not have a positive rule set, then a positive rule set is created automatically, and the rules for the table are added to the positive rule set. A subset rule can be added to positive rule set only, not to a negative rule set. Other rules in an existing rule set for the process are not affected. Additional rules can be added using either the DBMS_STREAMS_ADM package or the DBMS_RULE_ADM package.

Rules for INSERT, UPDATE, and DELETE statements are created automatically when you run this procedure, and these rules are given a system-generated rule name. The system-generated rule name is the table name with a sequence number appended to it. The sequence number is used to avoid naming conflicts. If the table name plus the sequence number is too long, then the table name is truncated. The ADD_SUBSET_RULES procedure is overloaded, and the system-generated rule names for INSERT, UPDATE, and DELETE statements are returned.

Examples

The following is an example of a rule condition that may be created for filtering DML changes containing an update operation when the dml_condition is region_id = 2 and the table_name is hr.regions:

:dml.get_object_owner() = 'HR' AND :dml.get_object_name() = 'REGIONS' AND 
:dml.is_null_tag() = 'Y' AND :dml.get_command_type() = 'UPDATE' AND (:dml.get_
value('NEW','"REGION_ID"') IS NOT NULL) AND (:dml.get_value('OLD','"REGION_ID"') 
IS NOT NULL) AND (:dml.get_value('OLD','"REGION_ID"').AccessNumber()=2) AND 
(:dml.get_value('NEW','"REGION_ID"').AccessNumber()=2)

ADD_TABLE_PROPAGATION_RULES Procedure

These procedures add table rules to the positive rule set for a propagation, or add table rules to the negative rule set for a propagation, and create the specified propagation if it does not exist.

Syntax

DBMS_STREAMS_ADM.ADD_TABLE_PROPAGATION_RULES(
   table_name              IN   VARCHAR2,
   streams_name            IN   VARCHAR2  DEFAULT NULL,
   source_queue_name       IN   VARCHAR2,
   destination_queue_name  IN   VARCHAR2,
   include_dml             IN   BOOLEAN   DEFAULT true,
   include_ddl             IN   BOOLEAN   DEFAULT false,
   include_tagged_lcr      IN   BOOLEAN   DEFAULT false,
   source_database         IN   VARCHAR2  DEFAULT NULL,
   dml_rule_name           OUT  VARCHAR2,
   ddl_rule_name           OUT  VARCHAR2,
   inclusion_rule          IN   BOOLEAN   DEFAULT true,
   and_condition           IN   VARCHAR2  DEFAULT NULL);

Parameters

Table 96-10  ADD_TABLE_PROPAGATION_RULES Procedure Parameters

(system_condition) AND (and_condition)

:lcr.get_tag() = HEXTORAW(''02'')

Usage Notes

This procedure creates DML and DDL rules automatically based on include_dml and include_ddl parameter values, respectively. A system-generated rule name is the table name with a sequence number appended to it. The sequence number is used to avoid naming conflicts. If the table name plus the sequence number is too long, then the table name is truncated. The overloaded ADD_TABLE_PROPAGATION_RULES procedure generates the rule names for DML and DDL changes. A propagation uses the rules created for filtering.

If no propagation job exists for the database link specified in the destination_queue_name parameter when this procedure is run, then a propagation job is created for use by the propagation. If a propagation job already exists for the specified database link, then the propagation uses the existing propagation job.

This procedure also configures propagation using the current user, and establishes a default propagation schedule. Only one propagation is allowed between the source queue and the destination queue.

Examples

The following is an example of a table rule condition that may be created for filtering DML statements:

:dml.get_object_owner() = 'HR' AND :dml.get_object_name() = 'LOCATIONS' 
AND :dml.is_null_tag() = 'Y' AND :dml.get_source_database_name() = 'DBS1.NET'

ADD_TABLE_RULES Procedures

These procedures add rules to a rule set of one of the following types of Streams clients:

• Capture process rules for capturing changes to a specified table when the streams_type parameter is set to capture. See "Capture Process Rules for Changes in the Redo Log" for more information about these rules.
• Apply process rules for applying logical change records (LCRs) in a queue that contain changes to a specified table when the streams_type parameter is set to apply. The rules may specify that the LCRs must be from a particular source database. See "Apply Process Rules for LCRs" for more information about these rules.
• Messaging client rules for dequeuing user-enqueued LCRs from a queue that contain changes to a specified table when the streams_type parameter is set to dequeue. The rules may specify that the LCRs must be from a particular source database. See "Messaging Client Rules for LCRs" for more information about these rules.

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

Syntax

DBMS_STREAMS_ADM.ADD_TABLE_RULES(
   table_name          IN   VARCHAR2,
   streams_type        IN   VARCHAR2,
   streams_name        IN   VARCHAR2 DEFAULT NULL,
   queue_name          IN   VARCHAR2 DEFAULT 'streams_queue',
   include_dml         IN   BOOLEAN  DEFAULT true,
   include_ddl         IN   BOOLEAN  DEFAULT false,
   include_tagged_lcr  IN   BOOLEAN  DEFAULT false,
   source_database     IN   VARCHAR2 DEFAULT NULL,
   dml_rule_name       OUT  VARCHAR2,
   ddl_rule_name       OUT  VARCHAR2,
   inclusion_rule      IN   BOOLEAN   DEFAULT true,
   and_condition       IN   VARCHAR2  DEFAULT NULL);

Parameters

Table 96-11  ADD_TABLE_RULES Procedure Parameters

(system_condition) AND (and_condition)

:lcr.get_tag() = HEXTORAW(''02'')

Usage Notes

This procedure creates the specified capture process, apply process, or messaging client if it does not exist.

This procedure creates DML and DDL rules automatically based on include_dml and include_ddl parameter values, respectively. A system-generated rule name is the table name with a sequence number appended to it. The sequence number is used to avoid naming conflicts. If the table name plus the sequence number is too long, then the table name is truncated. The overloaded ADD_TABLE_RULES procedure generates the rule names for DML and DDL changes. A capture process, apply process, or messaging client uses the rules created for filtering.

Examples

The following is an example of a table rule condition that may be created for DML changes:

:dml.get_object_owner() = 'HR' and :dml.get_object_name() = 'EMPLOYEES' 
AND :dml.is_null_tag() = 'Y' AND :dml.get_source_database_name() = 'DBS1.NET'

GET_SCN_MAPPING Procedure

This procedure gets information about the system change number (SCN) values to use for Streams capture and apply processes in a Streams replication environment. This information can be used for the following purposes:

• To recover transactions after point-in-time recovery is performed on a source database in a multiple source Streams environment
• To run flashback queries for the corresponding SCN at a source database and destination database in a Streams single source replication environment

  See Also: Oracle Streams Replication Administrator's Guide for information about point-in-time recovery and flashback queries in a Streams replication environment

Syntax

DBMS_STREAMS_ADM.GET_SCN_MAPPING(
   apply_name             IN  VARCHAR2,
   src_pit_scn            IN  NUMBER,
   dest_instantiation_scn OUT NUMBER,
   dest_start_scn         OUT NUMBER,
   dest_skip_txn_ids      OUT DBMS_UTILITY.NAME_ARRAY);

Parameters

Table 96-12  GET_SCN_MAPPING Procedure Parameters

MAINTAIN_SIMPLE_TABLESPACE Procedure

This procedure clones a simple tablespace from a source database at a destination database and uses Streams to maintain this tablespace at both databases. This procedure either can perform these actions directly, or it can generate a script that performs these actions.

Syntax

DBMS_STREAMS_ADM.MAINTAIN_SIMPLE_TABLESPACE(
   tablespace_name              IN VARCHAR2,
   source_directory_object      IN VARCHAR2,
   destination_directory_object IN VARCHAR2,
   destination_database         IN VARCHAR2,
   setup_streams                IN BOOLEAN   DEFAULT true,
   script_name                  IN VARCHAR2  DEFAULT NULL,
   script_directory_object      IN VARCHAR2  DEFAULT NULL,
   bi_directional               IN BOOLEAN   DEFAULT false);

Parameters

Table 96-13  MAINTAIN_SIMPLE_TABLESPACE Procedure Parameters

Usage Notes

Single Source and Bi-Directional Configurations

This procedure either sets up a single source Streams configuration with the local database as the source database, or it sets up a bi-directional Streams configuration with both databases acting as source and destination databases. The bi_directional parameter controls whether the Streams configuration is single source or bi-directional. The information about single source, bi-directional, and multi-directional Streams environments in the description for the MAINTAIN_TABLESPACES procedure also applies to this procedure.

Change Cycling and the MAINTAIN_SIMPLE_TABLESPACE Procedure

If the bi_directional is set to true, then this procedure configures bi-directional replication, but this procedure cannot be used to configure multi-directional replication where changes may be cycled back to a source database by a third database in the environment. The information about change cycling in the description for the MAINTAIN_TABLESPACES procedure also applies to this procedure.

DDL Changes Not Maintained

This procedure does not configure the Streams environment to maintain DDL changes to the tablespace nor to the database objects in the tablespace. For example, the Streams environment is not configured to replicate ALTER TABLESPACE statements on the tablespace, nor is it configured to replicate ALTER TABLE statements on tables in the tablespace. You may configure the Streams environment to maintain DDL changes manually or modify generated scripts to achieve this.

Privileges and Database Links Required by the MAINTAIN_SIMPLE_TABLESPACE Procedure

The user who runs the MAINTAIN_SIMPLE_TABLESPACE procedure should have DBA role. This user must have the necessary privileges to complete the following actions:

• Create SYS.AnyData queues, capture processes, propagations, and apply processes.
• Specify supplemental logging
• Run subprograms in the DBMS_STREAMS_ADM, DBMS_STREAMS_TABLESPACES_ADM, DBMS_FILE_TRANSFER, and DBMS_AQADM packages
• The necessary privileges to run the CLONE_SIMPLE_TABLESPACE procedure in the DBMS_STREAMS_TABLESPACES_ADM package at the source database. See CLONE_SIMPLE_TABLESPACE Procedure for the list of required privileges.
• The necessary privileges to run the ATTACH_SIMPLE_TABLESPACE procedure in the DBMS_STREAMS_TABLESPACES_ADM package at the destination database. See ATTACH_SIMPLE_TABLESPACE Procedure for the list of required privileges.
• Access the database specified in the destination_database parameter through a database link. This database link should have the same name as the global name of the destination database.

In addition, if the bi_directional parameter is set to true, then the corresponding user at the destination database must be able to use a database link to access the source database. This database link should have the same name as the global name of the source database.

To ensure that the user who runs this procedure has the necessary privileges, Oracle recommends that you configure a Streams administrator at each database. In this case, each database link should be should be created in the Streams administrator's schema.

Actions Performed by the MAINTAIN_SIMPLE_TABLESPACE Procedure

The actions performed by this procedure are the same as the actions performed by the MAINTAIN_TABLESPACES procedure, except that this procedure only can be used for a simple tablespace. A simple tablespace is a single, self-contained tablespace that uses only one datafile. This procedure cannot be used for a non simple tablespace or a set of tablespaces.

This procedure uses the default values for the parameters in the MAINTAIN_TABLESPACES procedure that do not exist in the MAINTAIN_SIMPLE_TABLESPACES procedure. For example, this procedure creates a capture process at the source database named capture, because that is the default value for the capture_name parameter in the MAINTAIN_TABLESPACES procedure.

MAINTAIN_TABLESPACES Procedure

This procedure clones a set of tablespaces from a source database at a destination database and uses Streams to maintain these tablespaces at both databases. This procedure either can perform these actions directly, or it can generate a script that performs these actions.

Syntax

DBMS_STREAMS_ADM.MAINTAIN_TABLESPACES(
   tablespace_names             IN DBMS_STREAMS_TABLESPACE_ADM.TABLESPACE_SET,
   source_directory_object      IN VARCHAR2,
   destination_directory_object IN VARCHAR2,
   destination_database         IN VARCHAR2,
   setup_streams                IN BOOLEAN   DEFAULT true,
   script_name                  IN VARCHAR2  DEFAULT NULL,
   script_directory_object      IN VARCHAR2  DEFAULT NULL,
   dump_file_name               IN VARCHAR2  DEFAULT NULL,
   source_queue_table           IN VARCHAR2  DEFAULT 'streams_queue_table',
   source_queue_name            IN VARCHAR2  DEFAULT 'streams_queue',
   source_queue_user            IN VARCHAR2  DEFAULT NULL,
   destination_queue_table      IN VARCHAR2  DEFAULT 'streams_queue_table',
   destination_queue_name       IN VARCHAR2  DEFAULT 'streams_queue',
   destination_queue_user       IN VARCHAR2  DEFAULT NULL,
   capture_name                 IN VARCHAR2  DEFAULT 'capture',
   propagation_name             IN VARCHAR2  DEFAULT NULL,
   apply_name                   IN VARCHAR2  DEFAULT NULL,
   log_file                     IN VARCHAR2  DEFAULT NULL,
   bi_directional               IN BOOLEAN   DEFAULT false);

Parameters

Table 96-14  MAINTAIN_TABLESPACES Procedure Parameters

Usage Notes

The specified set of tablespaces must be self-contained. In this context "self-contained" means that there are no references from inside the set of tablespaces pointing outside of the set of tablespaces. For example, if a partitioned table is partially contained in the set of tablespaces, then the set of tablespaces is not self-contained.

Single Source and Bi-Directional Configurations

This procedure either sets up a single source Streams configuration with the local database as the source database, or it sets up a bi-directional Streams configuration with both databases acting as source and destination databases. The bi_directional parameter controls whether the Streams configuration is single source or bi-directional. If bi_directional is false, then a capture process at the local database captures DML changes to the tables in the specified tablespace set, a propagation propagates these changes to the destination database, and an apply process at the destination database applies these changes. If bi_directional is true, then each database captures changes and propagates them to the other database, and each database applies changes from the other database.

If bi_directional is set to false, then this procedure does not configure bi-directional information sharing. Therefore, changes made to the tables in the tablespace set at the destination database are not shared with the source database, and the tablespaces are not kept in sync at the two databases, unless no changes are made to the tablespace objects at the destination database. However, if bi_directional is set to true, then Streams is configured to keep the tablespaces in sync at the two databases, even if both databases allow DML changes to the tablespace objects.

Both databases must be open when the actions are performed. Meet the following requirements when you use this procedure:

• Run this procedure at the intended source database. If bi_directional is set to true, then run this procedure at the database that contains the tablespace set to be cloned.
• If this procedure is generating a script only, then the database specified in the destination_database parameter does not need to be open when you run this procedure, but both databases must be open when you run the generated script.

  Note: You may need to configure conflict resolution if this procedure configures bi-directional replication.

  See Also: SET_UPDATE_CONFLICT_HANDLER Procedure Oracle Streams Replication Administrator's Guide for more information about conflict resolution

Change Cycling and the MAINTAIN_TABLESPACES Procedure

If the bi_directional is set to true, then this procedure configures bi-directional replication, but this procedure cannot be used to configure multi-directional replication where changes may be cycled back to a source database by a third database in the environment. For example, this procedure cannot be used to configure a Streams replication environment with three databases where each database shares changes with the other two databases in the environment. If this procedure is used to configure a three way replication environment such as this, then changes made at a source database would be cycled back to the same source database. In a valid three way replication environment, a particular change is made only once at each database.

To prevent change cycling in a bi-directional Streams replication environment, this procedure configures the environment in the following way:

• The apply process at each database applies changes with an apply tag that is unique to the environment. An apply tag is a Streams tag that is part of each redo record created by the apply process. For example, if this procedure configures databases sfdb.net and nydb.net for bi-directional replication, then assume that the apply tag for the apply process at sfdb.net is the hexidecimal equivalent of '1', and assume that the apply tag for the apply process at nydb.net is the hexidecimal equivalent of '2'.
• The capture process at each database captures all DML changes to the supported tables in the tablespace set, regardless of tags in the redo records for the changes.
• Each propagation propagates all DML changes to the supported tablespace set to the other database in the bi-directional replication environment, except for changes that originated at the other database. Continuing the example, the propagation at sfdb.net propagates all changes to nydb.net, except for changes with a tag value that is the hexidecimal equivalent of '1', because these changes originated at nydb.net. Similarly, the propagation at nydb.net propagates all changes to sfdb.net, except for changes with a tag value that is the hexidecimal equivalent of '2'.

This procedure can be used to configure a Streams replication environment that includes more than two databases, as long as changes made at a source database cannot cycle back to the same source database. For example, this procedure can be run multiple times to configure an environment in which a primary database shares changes with multiple secondary databases. Such an environment is sometimes called a "hub and spoke" environment.

You may configure the Streams environment manually to replicate changes in a multiple source environment where each source database shares changes with the other source databases, or you may modify generated scripts to achieve this.

DDL Changes Not Maintained

This procedure does not configure the Streams environment to maintain DDL changes to the tablespace set nor to the database objects in the tablespace set. For example, the Streams environment is not configured to replicate ALTER TABLESPACE statements on the tablespace, nor is it configured to replicate ALTER TABLE statements on tables in the tablespace. You may configure the Streams environment to maintain DDL changes manually or modify generated scripts to achieve this.

Privileges and Database Links Required by the MAINTAIN_TABLESPACES Procedure

The user who runs the MAINTAIN_TABLESPACES procedure should have DBA role. This user must have the necessary privileges to complete the following actions:

• Create SYS.AnyData queues, capture processes, propagations, and apply processes.
• Specify supplemental logging
• Run subprograms in the DBMS_STREAMS_ADM, DBMS_STREAMS_TABLESPACES_ADM, DBMS_FILE_TRANSFER, and DBMS_AQADM packages
• The necessary privileges to run the CLONE_TABLESPACES procedure in the DBMS_STREAMS_TABLESPACES_ADM package at the source database. See CLONE_TABLESPACES Procedure for the list of required privileges.
• The necessary privileges to run the ATTACH_TABLESPACES procedure in the DBMS_STREAMS_TABLESPACES_ADM package at the destination database. See ATTACH_TABLESPACES Procedure for the list of required privileges.
• Access the database specified in the destination_database parameter through a database link. This database link should have the same name as the global name of the destination database.

In addition, if the bi_directional parameter is set to true, then the corresponding user at the destination database must be able to use a database link to access the source database. This database link should have the same name as the global name of the source database.

To ensure that the user who runs this procedure has the necessary privileges, Oracle recommends that you configure a Streams administrator at each database. In this case, each database link should be should be created in the Streams administrator's schema.

Actions Performed by the MAINTAIN_TABLESPACES Procedure

This section describes the specific actions performed by this procedure. In the description, the source database is the database is the database where the MAINTAIN_TABLESPACES procedure is run, and the destination database is the database specified in the destination_database parameter.

First, at the source database, this procedure performs the following actions:

1. Adds supplemental log groups for all tables supported by Streams in the tablespace set
2. Configures a SYS.AnyData queue as a source queue that will stage changes to the database objects in the tablespace set

Next, if the bi_directional parameter is set to true, then this procedure performs the following actions at the source database (If the bi_directional parameter is set to false, then these actions are not performed, and the procedure continues at Step 5):

3. Configures a local apply process and adds rules to its positive rule set that instruct the apply process to apply DML changes to tables that are supported by Streams in the tablespace set. The apply process is configured to mark redo records with a tag value that is unique to the destination database, which is the source database of the changes.
4. Sets the key columns for tables that do not have a primary key using the SET_KEY_COLUMNS procedure in the DBMS_APPLY_ADM package

Next, this procedure performs the following actions at the source database:

5. Configures a propagation, and configures its rule sets to instruct the propagation to propagate changes from the source database to the destination database. If the bi_directional parameter is set to true, then the rule sets filter out changes that originated at the destination database.
6. Disables the propagation schedule for the propagation created in Step 5
7. Configures a local capture process and adds rules to its positive rule set that instruct the capture process to capture DML changes to tables that are supported by Streams in the tablespace set
8. Makes the specified tablespace set read-only
9. Clones the specified tablespace set using the CLONE_TABLESPACES procedure in the DBMS_STREAMS_TABLESPACE_ADM package. The Data Pump export dump file and the datafiles that comprise the cloned tablespace set are placed in the specified source directory as part of the clone tablespaces operation.
10. Makes the specified tablespace set read/write. Users and applications can resume operations on the tablespace set.
11. Starts the capture process configured in Step 7

Next, if the bi_directional parameter is set to true, then this procedure performs the following action at the source database (If the bi_directional parameter is set to false, then this action is not performed, and the procedure continues at Step 13):

12. Starts the apply process configured in Step 3

Next, this procedure performs the following action at the source database:

13. Uses the DBMS_FILE_TRANSFER package to copy the Data Pump export dump file and the datafiles for the tablespace set to the specified destination directory at the computer system running the destination database

Next, this procedure performs the following actions at the destination database:

14. Attaches the tablespace set using the ATTACH_TABLESPACES procedure in the DBMS_STREAMS_TABLESPACE_ADM package
15. Configures a local apply process and adds rules to its positive rule set that instruct the apply process to apply DML changes to tables that are supported by Streams in the tablespace set. The apply process is configured to mark redo records with a tag value that is unique to the source database of the changes.
16. Sets the key columns for tables that do not have a primary key using the SET_KEY_COLUMNS procedure in the DBMS_APPLY_ADM package
17. Configures a SYS.AnyData queue as a destination queue that will stage propagated DML changes to the tables in the tablespace set

Next, if the bi_directional parameter is set to true, then this procedure performs the following actions at the destination database (If the bi_directional parameter is set to false, then these actions are not performed, and the procedure continues at Step 24):

18. Adds supplemental log groups for all tables supported by Streams in the tablespace set
19. Configures a propagation, and configures its rule sets to instruct the propagation to propagate changes from this database to the source database. The rule sets filter out changes that originated at the source database.
20. Disables the propagation schedule for the propagation created in Step 19
21. Configures a local capture process and adds rules to its positive rule set that instruct the capture process to capture DML changes to tables that are supported by Streams in the tablespace set
22. Records the value of the current database SCN, and uses this value to set the instantiation SCNs of the objects in the tablespace set at the source database
23. Starts the capture process created in Step 21

Next, this procedure performs the following actions at the destination database:

24. Starts the apply process created in Step 15
25. Makes the tablespace set read/write

Next, if the bi_directional parameter is set to true, then this procedure performs the following action at the destination database (If the bi_directional parameter is set to false, then this action is not performed, and the procedure continues at Step 24):

26. Enables the propagation schedule for the propagation created in Step 19

Next, this procedure performs the final action at the source database:

27. Enables the propagation schedule for the propagation created in Step 5

To monitor the progress of the configuration, query the V$SESSION_LONGOPS dynamic performance view at the source database.

PURGE_SOURCE_CATALOG Procedure

This procedure removes all Streams data dictionary information at the local database for the specified object. You can use this procedure to remove Streams metadata that is not needed currently and will not be needed in the future.

Syntax

DBMS_STREAMS_ADM.PURGE_SOURCE_CATALOG(
   source_database     IN  VARCHAR2,
   source_object_name  IN  VARCHAR2,
   source_object_type  IN  VARCHAR2);

Parameters

Table 96-15 PURGE_SOURCE_CATALOG Procedure Parameters

Usage Notes

The global name of the source database containing the object must be specified for the source_database parameter. If the current database is not the source database for the object, then data dictionary information about the object is removed at the current database, not the source database.

For example, suppose changes to the hr.employees table at the dbs1.net source database are being applied to the hr.employees table at the dbs2.net destination database. Also, suppose hr.employees at dbs2.net is not a source at all. In this case, specifying dbs2.net as the source_database for this table results in an error. However, specifying dbs1.net as the source_database for this table while running the PURGE_SOURCE_CATALOG procedure at the dbs2.net database removes data dictionary information about the table at dbs2.net.

Do not run this procedure at a database if either of the following conditions are true:

• LCRs captured by the capture process for the object are or may be applied locally without reinstantiating the object.
• LCRs captured by the capture process for the object are or may be forwarded by the database without reinstantiating the object.

  Note: These conditions do not apply to LCRs that were not created by the capture process. That is, these conditions do not apply to user-created LCRs.

REMOVE_QUEUE Procedure

This procedure removes the specified SYS.AnyData queue.

Specifically, this procedure performs the following actions:

1. Waits until all current enqueue and dequeue transactions commit.
2. Stops the queue, which means that no further enqueues into the queue or dequeues from the queue are allowed.
3. Drops the queue.
4. If the drop_unused_queue_table parameter is set to true, then drops the queue table if it is empty and no other queues are using it.
5. If the cascade parameter is set to true, then drops all of the Streams clients that are using the queue.

   Note: The specified queue must be a SYS.AnyData queue.

Syntax

DBMS_STREAMS_ADM.REMOVE_QUEUE(
   queue_name               IN  VARCHAR2,
   cascade                  IN  BOOLEAN  DEFAULT false,
   drop_unused_queue_table  IN  BOOLEAN  DEFAULT true);

Parameters

Table 96-16 REMOVE_QUEUE Procedure Parameters

REMOVE_RULE Procedure

This procedure removes the specified rule or all rules from the rule set associated with the specified capture process, apply process, propagation, or messaging client.

If this procedure results in an empty positive rule set for a messaging client, then the messaging client is dropped automatically.

Syntax

DBMS_STREAMS_ADM.REMOVE_RULE(
   rule_name         IN  VARCHAR2,
   streams_type      IN  VARCHAR2,
   streams_name      IN  VARCHAR2,
   drop_unused_rule  IN  BOOLEAN  DEFAULT true,
   inclusion_rule    IN  BOOLEAN  DEFAULT true);

Parameters

Table 96-17  REMOVE_RULE Procedure Parameters

REMOVE_STREAMS_CONFIGURATION Procedure

This procedure removes the Streams configuration at the local database.

Syntax

DBMS_STREAMS_ADM.REMOVE_STREAMS_CONFIGURATION;

Usage Notes

Specifically, this procedure performs the following actions at the local database:

• Drops all capture processes
• If any tables have been prepared for instantiation, then aborts preparation for instantiation for the table using the ABORT_TABLE_INSTANTIATION procedure in the DBMS_CAPTURE_ADM package
• If any schemas have been prepared for instantiation, then aborts preparation for instantiation for the schema using the ABORT_SCHEMA_INSTANTIATION procedure in the DBMS_CAPTURE_ADM package
• If the database has been prepared for instantiation, then aborts preparation for instantiation for the database using the ABORT_GLOBAL_INSTANTIATION procedure in the DBMS_CAPTURE_ADM package
• Drops propagations that were created using either the DBMS_STREAMS_ADM package or the DBMS_PROPAGATION_ADM package. Before a propagation is dropped, its propagation job is disabled. Does not drop propagations that were created using the DBMS_AQADM package.
• Disables all propagation jobs used by propagations
• Drops all apply processes. If there are apply errors in the error queue for an apply process, then this procedure deletes these apply errors before it drops the apply process.
• Removes specifications for DDL handlers used by apply processes, but does not delete the PL/SQL procedures used by these handlers
• Removes specifications for message handlers used by apply processes, but does not delete the PL/SQL procedures used by these handlers
• Removes specifications for precommit handlers used by apply processes, but does not delete the PL/SQL procedures used by these handlers
• Removes the instantiation SCN and ignore SCN for each apply object and schema and for the entire database
• Removes messaging clients
• Unsets message notification specifications that were set using the SET_MESSAGE_NOTIFICATION procedure in the DBMS_STREAMS_ADM package
• Removes specifications for DML handlers and error handlers, but does not delete the PL/SQL procedures used by these handlers
• Removes update conflict handlers
• Removes specifications for substitute key columns for apply tables
• Drops rules that were created using the DBMS_STREAMS_ADM package. Does not drop rules that were created using the DBMS_RULE_ADM package.

This procedure stops capture processes and apply processes before it drops them.

SET_MESSAGE_NOTIFICATION Procedure

This procedure sets a notification for messages that can be dequeued by a specified Streams messaging client from a specified queue. A notification is sent when a message is enqueued into the specified queue and the specified messaging client can dequeue the message because the message satisfies its rule sets.

Syntax

DBMS_STREAMS_ADM.SET_MESSAGE_NOTIFICATION(
   streams_name          IN  VARCHAR2,
   notification_action   IN  VARCHAR2,
   notification_type     IN  VARCHAR2     DEFAULT 'PROCEDURE',
   notification_context  IN  SYS.AnyData  DEFAULT NULL,
   include_notification  IN  BOOLEAN      DEFAULT true,
   queue_name            IN  VARCHAR2     DEFAULT 'streams_queue');

Parameters

Table 96-18  SET_MESSAGE_NOTIFICATION Procedure Parameters

SYS.AnyData.ConvertRaw(HEXTORAW('FF'))

Usage Notes

You can specify one of the following types of notifications:

• An email address to which message notifications are sent. When a relevant message is enqueued into the queue, an email with the message properties is mailed to the specified email address.
• A PL/SQL procedure to be invoked on a notification. When a relevant message is enqueued into the queue, the specified PL/SQL procedure is invoked with the message properties. This PL/SQL procedure may dequeue the message.
• An HTTP URL to which the notification is posted. When a relevant message is enqueued into the queue, a notification with the message properties is posted to the specified URL specified.

A client does not need to be connected to the database to receive a notification.

If you register for email notifications, then you should use the DBMS_AQELM package to set the host name and port name for the SMTP server that will be used by the database to send email notifications. If required, then you should set the send-from email address, which is set by the database as the sent from field. You need a Java-enabled database to use this feature.

If you register for HTTP notifications, you may want to use the DBMS_AQELM package to set the host name and port number for the proxy server and a list of no-proxy domains that will be used by the database to post HTTP notifications.

Each notification is an AQXmlNotification, which includes of the following:

• notification_options, which includes the following:
  • destination - The destination queue from which the message was dequeued
  • consumer_name - The name of the messaging client that dequeued the message
• message_set - The set of message properties

  See Also: The documentation for the DBMS_AQELM package for more information on email notifications and HTTP notifications Oracle Streams Concepts and Administration for more information about setting message notifications Oracle Streams Advanced Queuing User's Guide and Reference and Oracle XML DB Developer's Guide for more information about message notifications and XML Oracle Streams Concepts and Administration for more information about how rules are used in Streams

Examples

If you use a message notification procedure, then this PL/SQL procedure must have the following signature:

PROCEDURE procedure_name(
  context  IN  SYS.AnyData,
  reginfo  IN  SYS.AQ$_REG_INFO,
  descr    IN  SYS.AQ$_DESCRIPTOR);

Here, procedure_name stands for the name of the procedure. The procedure is a PLSQLCALLBACK data structure that specifies the user-defined PL/SQL procedure to be invoked on message notification.

The following is a simple example of a notification procedure that dequeues a message of type oe.user_msg using the message identifier and consumer name sent by the notification:

CREATE OR REPLACE PROCEDURE oe.notification_dequeue(
  context  SYS.AnyData, 
  reginfo  SYS.AQ$_REG_INFO, 
  descr    SYS.AQ$_DESCRIPTOR)
AS
  dequeue_options     DBMS_AQ.DEQUEUE_OPTIONS_T;
  message_properties  DBMS_AQ.MESSAGE_PROPERTIES_T;
  message_handle      RAW(16);
  message             oe.user_msg;
BEGIN
  -- Get the message identifier and consumer name from the descriptor
  dequeue_options.msgid := descr.msg_id;
  dequeue_options.consumer_name := descr.consumer_name;
  -- Dequeue the message
  DBMS_AQ.DEQUEUE(
    queue_name         => descr.queue_name,
    dequeue_options    => dequeue_options,
    message_properties => message_properties,
    payload            => message,
    msgid              => message_handle);
  COMMIT;
END;
/

SET_RULE_TRANSFORM_FUNCTION Procedure

This procedure sets or removes the transformation function name for a rule-based transformation.

Syntax

DBMS_STREAMS_ADM.SET_RULE_TRANSFORM_FUNCTION(
   rule_name           IN  VARCHAR2,
   transform_function  IN  VARCHAR2);

Parameters

Table 96-19 SET_RULE_TRANSFORM_FUNCTION Procedure Parameters

Usage Notes

This procedure modifies the specified rule's action context to specify the transformation. 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 an event. The client of the rules engine can be a user-created application or an internal feature of Oracle, such as Streams. The Streams clients include capture processes, propagations, apply processes, and messaging clients. 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 rule-based transformation in Streams always consists of the following name-value pair in an action context:

• The name is STREAMS$_TRANSFORM_FUNCTION.
• The value is a SYS.AnyData instance containing a PL/SQL function name specified as a VARCHAR2. This function performs the transformation.

The user that calls the transformation function must have EXECUTE privilege on the function. The following list describes which user calls the transformation function:

• If a transformation is specified for a rule used by a capture process, then the user who calls the transformation function is the capture user for the capture process.
• If a transformation is specified for a rule used by a propagation, then the user who calls the transformation function is the owner of the source queue for the propagation.
• If a transformation is specified on a rule used by an apply process, then the user who calls the transformation function is the apply user for the apply process.
• If a transformation is specified on a rule used by a messaging client, then the user who calls the transformation function is the user who invokes the messaging client.

  Note: This procedure does not verify that the specified transformation function exists. If the function does not exist, then an error is raised when a Streams client tries to invoke the transformation function.

SET_UP_QUEUE Procedure

This procedure creates a queue table and a SYS.AnyData queue for use with the capture, propagate, and apply functionality of Streams.

Syntax

DBMS_STREAMS_ADM.SET_UP_QUEUE(
   queue_table     IN  VARCHAR2  DEFAULT 'streams_queue_table',
   storage_clause  IN  VARCHAR2  DEFAULT NULL,
   queue_name      IN  VARCHAR2  DEFAULT 'streams_queue',
   queue_user      IN  VARCHAR2  DEFAULT NULL,
   comment         IN  VARCHAR2  DEFAULT NULL);

Parameters

Table 96-20  SET_UP_QUEUE Procedure Parameters

Usage Notes

Set up includes the following actions:

• If the specified queue table does not exist, then this procedure runs the CREATE_QUEUE_TABLE procedure in the DBMS_AQADM package to create the queue table with the specified storage clause.
• If the specified queue name does not exist, then this procedure runs the CREATE_QUEUE procedure in the DBMS_AQADM package to create the queue.
• This procedure starts the queue.
• If a queue user is specified, then this procedure configures this user as a secure queue user of the queue and grants ENQUEUE and DEQUEUE privileges on the queue to the specified queue user.

  To configure the queue user as a secure queue user, this procedure creates an Advanced Queuing agent with the same name as the user name, if one does not already exist. If an agent with this name already exists and is associated with the queue user only, then it is used. SET_UP_QUEUE then runs the ENABLE_DB_ACCESS procedure in the DBMS_AQADM package, specifying the agent and the user.

This procedure creates a SYS.AnyData queue that is both a secure queue and a transactional queue.