23 DBMS_AQADM

The DBMS_AQADM package provides procedures to manage Oracle Database Advanced Queuing (AQ) configuration and administration information.

See Also:

This chapter contains the following topics:

23.1 DBMS_AQADM Security Model

Initially, only SYS and SYSTEM have execution privilege for the procedures in DBMS_AQADM and DBMS_AQ. Users who have been granted EXECUTE rights to DBMS_AQ and DBMS_AQADM are able to create, manage, and use queues in their own schemas. The MANAGE_ANY AQ system privilege is used to create and manage queues in other schemas and can be granted and revoked through DBMS_AQADM.GRANT_SYSTEM_PRIVILEGE and DBMS_AQADM.REVOKE_SYSTEM_PRIVILEGE respectively. Starting from Oracle Database 12c Release 2, MANAGE_ANY privilege will not allow access to SYS owned queues by users other than SYS.

User Roles

The database administrator has the option of granting the system privileges ENQUEUE_ANY and DEQUEUE_ANY, exercising DBMS_AQADM.GRANT_SYSTEM_PRIVILEGE and DBMS_AQADM.REVOKE_SYSTEM_PRIVILEGE directly to a database user, if you want the user to have this level of control.

The application developer gives rights to a queue by granting and revoking privileges at the object level by exercising DBMS_AQADM.GRANT_QUEUE_PRIVILEGE and DBMS_AQADM.REVOKE_QUEUE_PRIVILEGE. Starting from Oracle Database 12c Release 2, ENQUEUE_ANY and DEQUEUE_ANY privileges will not allow access to SYS owned queues by users other than SYS.

See Also:

Security Required for Propagation

Propagation jobs are owned by SYS, but the propagation occurs in the security context of the queue table owner. Previously propagation jobs were owned by the user scheduling propagation, and propagation occurred in the security context of the user setting up the propagation schedule. The queue table owner must be granted EXECUTE privileges on the DBMS_AQADM package. Otherwise, the Oracle Database snapshot processes do not propagate and generate trace files with the error identifier SYS.DBMS_AQADM not defined. Private database links owned by the queue table owner can be used for propagation. The username specified in the connection string must have EXECUTE access on the DBMS_AQ and DBMS_AQADM packages on the remote database.

See Also:

Oracle Database Advanced Queuing User's Guide for more information on security required for propagation.

Queue Table Migration

The MIGRATE_QUEUE_TABLE procedure requires that the EXECUTE privilege on DBMS_AQADM be granted to the queue table owner, who is probably an ordinary queue user. If you do not want ordinary queue users to be able to create and drop queues and queue tables, add and delete subscribers, and so forth, then you must revoke the EXECUTE privilege as soon as the migration is done.

See Also:

23.2 DBMS_AQADM Constants

When using enumerated constants, such as INFINITE, TRANSACTIONAL, or NORMAL_QUEUE, the symbol must be specified with the scope of the packages defining it. All types associated with the administrative interfaces must be prepended with DBMS_AQADM. For example: DBMS_AQADM.NORMAL_QUEUE.

Table 23-1 Enumerated Types in the Administrative Interface

Parameter Options

retention

0, 1, 2...INFINITE

message_grouping

TRANSACTIONAL, NONE

queue_type

NORMAL_QUEUE, EXCEPTION_QUEUE, NON_PERSISTENT_QUEUE

See Also:

For more information on the Java classes and data structures used in both DBMS_AQ and DBMS_AQADM, see the DBMS_AQ package.

23.3 DBMS_AQADM Subprogram Groups

This section lists and describes the DBMS_AQADM subprogram groups.

23.3.1 DBMS_AQADM Queue Table Subprograms

This section lists and describes the DBMS_AQADM Queue Table subprograms.

Table 23-2 Queue Table Subprograms

Subprograms Description

ALTER_QUEUE_TABLE Procedure

Alters the existing properties of a queue table

CREATE_QUEUE_TABLE Procedure

Creates a queue table for messages of a predefined type

DROP_QUEUE_TABLE Procedure

Drops an existing queue table

ENABLE_JMS_TYPES Procedure

A precondition for the enqueue of JMS types and XML types

MIGRATE_QUEUE_TABLE Procedure

Upgrades an 8.0-compatible queue table to an 8.1-compatible or higher queue table, or downgrades an 8.1-compatible or higher queue table to an 8.0-compatible queue table

PURGE_QUEUE_TABLE Procedure

Purges messages from queue tables

23.3.2 DBMS_AQADM Privilege Subprograms

This sections lists and describes the DBMS_AQADM Privilege subprograms.

Table 23-3 Privilege Subprograms

Subprograms Description

GRANT_QUEUE_PRIVILEGE Procedure

Grants privileges on a queue to users and roles

GRANT_SYSTEM_PRIVILEGE Procedure

Grants Oracle Database Advanced Queuing system privileges to users and roles

REVOKE_QUEUE_PRIVILEGE Procedure

Revokes privileges on a queue from users and roles

REVOKE_SYSTEM_PRIVILEGE Procedure

Revokes Oracle Database Advanced Queuing system privileges from users and roles

23.3.3 DBMS_AQADM Queue Subprograms

This sections lists and describes the DBMS_AQADM Queue subprograms.

Table 23-4 Queue Subprograms

Subprograms Description

ALTER_QUEUE Procedure

Alters existing properties of a queue

CREATE_NP_QUEUE Procedure

Creates a nonpersistent RAW queue

CREATE_QUEUE Procedure

Creates a queue in the specified queue table

CREATE_SHARDED_QUEUE Procedure

Creates a queue and its queue table for a sharded queue all together.

DROP_SHARDED_QUEUE Procedure

Drops an existing sharded queue from the database queuing system

ALTER_SHARDED_QUEUE Procedure

Alters an sharded queue in the database queuing system

CREATE_EXCEPTION_QUEUE Procedure

Creates an exception queue for a sharded queue

DROP_QUEUE Procedure

Drops an existing queue

QUEUE_SUBSCRIBERS Function

Returns the subscribers to an 8.0-compatible multiconsumer queue in the PL/SQL index by table collection type DBMS_AQADM.AQ$_subscriber_list_t

START_QUEUE Procedure

Enables the specified queue for enqueuing or dequeuing

STOP_QUEUE Procedure

Disables enqueuing or dequeuing on the specified queue

23.3.4 DBMS_AQADM Subscriber Subprograms

This sections lists and describes the DBMS_AQADM Subscriber subprograms.

Table 23-5 Subscriber Subprograms

Subprograms Description

ADD_SUBSCRIBER Procedure

Adds a default subscriber to a queue

ALTER_SUBSCRIBER Procedure

Alters existing properties of a subscriber to a specified queue

REMOVE_SUBSCRIBER Procedure

Removes a default subscriber from a queue

23.3.5 DBMS_AQADM Propagation Subprograms

This section lists and describes the DBMS_AQADM propagation subprograms.

Table 23-6 Propagation Subprograms

Subprograms Description

ALTER_PROPAGATION_SCHEDULE Procedure

Alters parameters for a propagation schedule

DISABLE_PROPAGATION_SCHEDULE Procedure

Disables a propagation schedule

ENABLE_PROPAGATION_SCHEDULE Procedure

Enables a previously disabled propagation schedule

SCHEDULE_PROPAGATION Procedure

Schedules propagation of messages from a queue to a destination identified by a specific database link

UNSCHEDULE_PROPAGATION Procedure

Unschedules previously scheduled propagation of messages from a queue to a destination identified by a specific database link

VERIFY_QUEUE_TYPES Procedure

Verifies that the source and destination queues have identical types

23.3.6 DBMS_AQADM Miscellaneous Subprograms

This section lists and describes the DBMS_AQADM miscellaneous subprograms.

Table 23-7 Miscellaneous Subprograms

Subprograms Description

GET_QUEUE_PARAMETER Procedure

Used to get different parameters for sharded queues at queue or database level.

GET_MAX_STREAMS_POOL Procedure

Retrieves the value of Oracle Database Advanced Queuing maximum streams pool memory limit

GET_MIN_STREAMS_POOL Procedure

Retrieves the value of Oracle Database Advanced Queuing minimum streams pool memory limit

GET_WATERMARK Procedure

Retrieves the value of watermark set by the SET_WATERMARK Procedure

SET_QUEUE_PARAMETER Procedure

Used to set different parameters for sharded queues at queue or database level.

SET_MAX_STREAMS_POOL Procedure

Used for Oracle Database Advanced Queuing to specify and limit maximum streams pool memory use

SET_MIN_STREAMS_POOL Procedure

Used for Oracle Database Advanced Queuing to specify and limit minimum streams pool memory use

SET_WATERMARK Procedure

Used for Oracle Database Advanced Queuing notification to specify and limit memory use

UNSET_QUEUE_PARAMETER Procedure

Used to unset different parameters for sharded queues at queue or database level.

23.3.7 DBMS_AQADM Agent Subprograms

This section lists and describes the DBMS_AQADM agent subprograms.

Table 23-8 Oracle Streams AQ Agent Subprograms

Subprograms Description

ALTER_AQ_AGENT Procedure

Alters an agent registered for Oracle Database Advanced Queuing Internet access, and an Oracle Database Advanced Queuing agent that accesses secure queues

CREATE_AQ_AGENT Procedure

Registers an agent for Oracle Database Advanced Queuing Internet access using HTTP/SMTP protocols, and creates an Oracle Database Advanced Queuing agent to access secure queues

DISABLE_DB_ACCESS Procedure

Revokes the privileges of a specific database user from an Oracle Database Advanced Queuing Internet agent

DROP_AQ_AGENT Procedure

Drops an agent that was previously registered for Oracle Database Advanced Queuing Internet access

ENABLE_DB_ACCESS Procedure

Grants an Oracle Database Advanced Queuing Internet agent the privileges of a specific database user

23.3.8 DBMS_AQADM Alias Subprograms

This section lists and describes the DBMS_AQADM alias subprograms.

Table 23-9 Alias Subprograms

Subprograms Description

ADD_ALIAS_TO_LDAP Procedure

Creates an alias for a queue, agent, or a JMS ConnectionFactory in LDAP

DEL_ALIAS_FROM_LDAP Procedure

Drops an alias for a queue, agent, or JMS ConnectionFactory in LDAP

23.4 Summary of DBMS_AQADM Subprograms

This section lists and describes the DBMS_AQADM package subprograms.

Table 23-10 DBMS_AQADM Package Subprograms

Subprograms Description

ADD_ALIAS_TO_LDAP Procedure

Creates an alias for a queue, agent, or a JMS ConnectionFactory in LDAP

ADD_SUBSCRIBER Procedure

Adds a default subscriber to a queue

ALTER_AQ_AGENT Procedure

Alters an agent registered for Oracle Database Advanced Queuing Internet access, and an Oracle Database Advanced Queuing agent that accesses secure queues

ALTER_PROPAGATION_SCHEDULE Procedure

Alters parameters for a propagation schedule

ALTER_QUEUE Procedure

Alters existing properties of a queue

ALTER_QUEUE_TABLE Procedure

Alters the existing properties of a queue table

ALTER_SHARDED_QUEUE Procedure

Provides user the ability to alter the cache_hint and comment for the sharded queue

Starting with Oracle Database 20c, sharded queues are deprecated and will be desupported in a futur release. Use Transactional Event Queues(TEQ) instead.

ALTER_SUBSCRIBER Procedure

Alters existing properties of a subscriber to a specified queue

ALTER_TRANSACTIONAL_EVENT_QUEUE Procedure

Provides user the ability to alter the cache_hint and comment for the TEQ queue

CREATE_AQ_AGENT Procedure

Registers an agent for Oracle Database Advanced Queuing Internet access using HTTP/SMTP protocols, and creates an Oracle Database Advanced Queuing agent to access secure queues

CREATE_NP_QUEUE Procedure

Creates a nonpersistent RAW queue

CREATE_QUEUE Procedure

Creates a queue in the specified queue table

CREATE_SHARDED_QUEUE Procedure

Creates a queue and its queue table for a sharded queue all together.

Starting with Oracle Database 20c, sharded queues are deprecated and will be desupported in a futur release. Use Transactional Event Queues(TEQ) instead.

CREATE_EXCEPTION_QUEUE Procedure

Creates an exception queue.

Starting with Oracle Database 20c, sharded queues are deprecated and will be desupported in a futur release. Use Transactional Event Queues(TEQ) instead.

CREATE_EQ EXCEPTION_QUEUE Procedure

Creates an exception queue.

CREATE_TRANSACTIONAL_EVENT_QUEUE Procedure

Creates a queue and its queue table for a Transactional Event Queue (TEQ).

CREATE_QUEUE_TABLE Procedure

Creates a queue table for messages of a predefined type

DEL_ALIAS_FROM_LDAP Procedure

Drops an alias for a queue, agent, or JMS ConnectionFactory in LDAP

DISABLE_DB_ACCESS Procedure

Revokes the privileges of a specific database user from an Oracle Database Advanced Queuing Internet agent

DISABLE_PROPAGATION_SCHEDULE Procedure

Disables a propagation schedule

DROP_AQ_AGENT Procedure

Drops an agent that was previously registered for Oracle Database Advanced Queuing Internet access

DROP_QUEUE Procedure

Drops an existing queue

DROP_SHARDED_QUEUE Procedure

Drops an existing sharded queue from the database queuing system

Starting with Oracle Database 20c, sharded queues are deprecated and will be desupported in a futur release. Use Transactional Event Queues(TEQ) instead.

DROP_TRANSACTIONAL_EVENT_QUEUE Procedure

Drops an existing TEQ queue from the database queuing system

DROP_QUEUE_TABLE Procedure

Drops an existing queue table

ENABLE_DB_ACCESS Procedure

Grants an Oracle Database Advanced Queuing Internet agent the privileges of a specific database user

ENABLE_JMS_TYPES Procedure

A precondition for the enqueue of JMS types and XML types

ENABLE_PROPAGATION_SCHEDULE Procedure

Enables a previously disabled propagation schedule

GET_MAX_STREAMS_POOL Procedure

Retrieves the value of Oracle Database Advanced Queuing maximum streams pool memory limit

GET_MIN_STREAMS_POOL Procedure

Retrieves the value of Oracle Database Advanced Queuing minimum streams pool memory limit

GET_QUEUE_PARAMETER Procedure

Used to get different parameters for sharded queues at queue or database level.

GET_WATERMARK Procedure

Retrieves the value of watermark set by the SET_WATERMARK Procedure

GRANT_QUEUE_PRIVILEGE Procedure

Grants privileges on a queue to users and roles

GRANT_SYSTEM_PRIVILEGE Procedure

Grants Oracle Database Advanced Queuing system privileges to users and roles

MIGRATE_QUEUE_TABLE Procedure

Upgrades an 8.0-compatible queue table to an 8.1-compatible or higher queue table, or downgrades an 8.1-compatible or higher queue table to an 8.0-compatible queue table

PURGE_QUEUE_TABLE Procedure

Purges messages from queue tables

QUEUE_SUBSCRIBERS Function

Returns the subscribers to an 8.0-compatible multiconsumer queue in the PL/SQL index by table collection type DBMS_AQADM.AQ$_subscriber_list_t

REMOVE_SUBSCRIBER Procedure

Removes a default subscriber from a queue

REVOKE_QUEUE_PRIVILEGE Procedure

Revokes privileges on a queue from users and roles

REVOKE_SYSTEM_PRIVILEGE Procedure

Revokes Oracle Database Advanced Queuing system privileges from users and roles

SCHEDULE_PROPAGATION Procedure

Schedules propagation of messages from a queue to a destination identified by a specific database link

SET_QUEUE_PARAMETER Procedure

Used to set different parameters for sharded queues at queue or database level.

SET_MAX_STREAMS_POOL Procedure

Used for Oracle Database Advanced Queuing to specify and limit maximum streams pool memory use

SET_MIN_STREAMS_POOL Procedure

Used for Oracle Database Advanced Queuing to specify and limit minimum streams pool memory use

SET_WATERMARK Procedure

Used for Oracle Database Advanced Queuing notification to specify and limit memory use

START_QUEUE Procedure

Enables the specified queue for enqueuing or dequeuing

STOP_QUEUE Procedure

Disables enqueuing or dequeuing on the specified queue

UNSCHEDULE_PROPAGATION Procedure

Unschedules previously scheduled propagation of messages from a queue to a destination identified by a specific database link

UNSET_QUEUE_PARAMETER Procedure

Used to unset different parameters for sharded queues at queue or database level.

VERIFY_QUEUE_TYPES Procedure

Verifies that the source and destination queues have identical types

23.4.1 ADD_ALIAS_TO_LDAP Procedure

This procedure creates an alias for a queue, agent, or a JMS ConnectionFactory in LDAP. The alias will be placed directly under the database server's distinguished name in LDAP hierarchy.

Syntax

DBMS_AQADM.ADD_ALIAS_TO_LDAP(
   alias          IN VARCHAR2,
   obj_location   IN VARCHAR2);

Parameters

Table 23-11 ADD_ALIAS_TO_LDAP Procedure Parameters

Parameter Description

alias

Name of the alias. Example: west_shipping.

obj_location

The distinguished name of the object (queue, agent or connection factory) to which alias refers.

Usage Notes

This method can be used to create aliases for queues, agents, and JMS ConnectionFactory objects. These object must exist before the alias is created. These aliases can be used for JNDI lookup in JMS and Oracle Database Advanced Queuing Internet access.

23.4.2 ADD_SUBSCRIBER Procedure

This procedure adds a default subscriber to a queue.

Syntax

DBMS_AQADM.ADD_SUBSCRIBER (
   queue_name      IN    VARCHAR2,
   subscriber      IN    sys.aq$_agent,
   rule            IN    VARCHAR2 DEFAULT NULL,
   transformation  IN    VARCHAR2 DEFAULT NULL
   queue_to_queue  IN    BOOLEAN DEFAULT FALSE,
   delivery_mode   IN    PLS_INTEGER DEFAULT DBMS_AQADM.PERSISTENT);

Parameters

Table 23-12 ADD_SUBSCRIBER Procedure Parameters

Parameter Description

queue_name

Name of the queue.

subscriber

Agent on whose behalf the subscription is being defined.

rule

A conditional expression based on the message properties, the message data properties and PL/SQL functions. A rule is specified as a Boolean expression using syntax similar to the WHERE clause of a SQL query. This Boolean expression can include conditions on message properties, user data properties (object payloads only), and PL/SQL or SQL functions (as specified in the where clause of a SQL query). Currently supported message properties are priority and corrid.

To specify rules on a message payload (object payload), use attributes of the object type in clauses. You must prefix each attribute with tab.user_data as a qualifier to indicate the specific column of the queue table that stores the payload. The rule parameter cannot exceed 4000 characters.

transformation

Specifies a transformation that will be applied when this subscriber dequeues the message. The source type of the transformation must match the type of the queue. If the subscriber is remote, then the transformation is applied before propagation to the remote queue.

queue_to_queue

If TRUE, propagation is from queue-to-queue.

delivery_mode

The administrator may specify one of DBMS_AQADM.PERSISTENT, DBMS_AQADM.BUFFERED, or DBMS_AQADM.PERSISTENT_OR_BUFFERED for the delivery mode of the messages the subscriber is interested in. This parameter will not be modifiable by ALTER_SUBSCRIBER.

Usage Notes

A program can enqueue messages to a specific list of recipients or to the default list of subscribers. This operation only succeeds on queues that allow multiple consumers. This operation takes effect immediately, and the containing transaction is committed. Enqueue requests that are executed after the completion of this call will reflect the new behavior.

Any string within the rule must be quoted:

rule   => 'PRIORITY <= 3 AND CORRID =  ''FROM JAPAN'''
 

Note that these are all single quotation marks.

23.4.3 ALTER_AQ_AGENT Procedure

This procedure alters an agent registered for Oracle Database Advanced Queuing Internet access. It is also used to alter an Oracle Database Advanced Queuing agent that accesses secure queues.

Syntax

DBMS_AQADM.ALTER_AQ_AGENT (
  agent_name                IN VARCHAR2,
  certificate_location      IN VARCHAR2 DEFAULT NULL,
  enable_http               IN BOOLEAN DEFAULT FALSE,
  enable_smtp               IN BOOLEAN DEFAULT FALSE,
  enable_anyp               IN BOOLEAN DEFAULT FALSE )

Parameters

Table 23-13 ALTER_AQ_AGENT Procedure Parameters

Parameter Description

agent_name

Specifies the username of the Oracle Database Advanced Queuing Internet agent.

certification_location

Agent's certificate location in LDAP (default is NULL). If the agent is allowed to access Oracle Database Advanced Queuing through SMTP, then its certificate must be registered in LDAP. For access through HTTP, the certificate location is not required.

enable_http

TRUE means the agent can access Oracle Database Advanced Queuing through HTTP. FALSE means the agent cannot access Oracle Database Advanced Queuing through HTTP.

enable_smtp

TRUE means the agent can access Oracle Database Advanced Queuing through SMTP (e-mail). FALSE means the agent cannot access Oracle Database Advanced Queuing through SMTP.

enable_anyp

TRUE means the agent can access Oracle Database Advanced Queuing through any protocol (HTTP or SMTP).

23.4.4 ALTER_PROPAGATION_SCHEDULE Procedure

This procedure alters parameters for a propagation schedule.

Syntax

DBMS_AQADM.ALTER_PROPAGATION_SCHEDULE ( 
   queue_name           IN    VARCHAR2, 
   destination          IN    VARCHAR2 DEFAULT NULL,
   duration             IN    NUMBER   DEFAULT NULL, 
   next_time            IN    VARCHAR2 DEFAULT NULL, 
   latency              IN    NUMBER   DEFAULT 60,
   destination_queue    IN    VARCHAR2 DEFAULT NULL);

Parameters

Table 23-14 ALTER_PROPAGATION_SCHEDULE Procedure Parameters

Parameter Description

queue_name

Name of the source queue whose messages are to be propagated, including the schema name. If the schema name is not specified, then it defaults to the schema name of the user.

destination

Destination database link. Messages in the source queue for recipients at this destination are propagated. If it is NULL, then the destination is the local database and messages are propagated to other queues in the local database. The length of this field is currently limited to 128 bytes, and if the name is not fully qualified, then the default domain name is used.

duration

Duration of the propagation window in seconds. A NULL value means the propagation window is forever or until the propagation is unscheduled.

next_time

Date function to compute the start of the next propagation window from the end of the current window. If this value is NULL, then propagation is stopped at the end of the current window. For example, to start the window at the same time every day, next_time should be specified as SYSDATE + 1 - duration/86400.

latency

Maximum wait, in seconds, in the propagation window for a message to be propagated after it is enqueued. The default value is 60. Caution: if latency is not specified for this call, then latency will over-write any existing value with the default value.

For example, if the latency is 60 seconds and there are no messages to be propagated during the propagation window, then messages from that queue for the destination are not propagated for at least 60 more seconds. It will be at least 60 seconds before the queue will be checked again for messages to be propagated for the specified destination. If the latency is 600, then the queue will not be checked for 10 minutes and if the latency is 0, then a job queue process will be waiting for messages to be enqueued for the destination and as soon as a message is enqueued it will be propagated.

destination_queue

Name of the target queue to which messages are to be propagated in the form of a dblink

23.4.5 ALTER_QUEUE Procedure

This procedure alters existing properties of a queue. The parameters max_retries, retention_time, and retry_delay are not supported for nonpersistent queues.

Syntax

DBMS_AQADM.ALTER_QUEUE (
   queue_name        IN    VARCHAR2,
   max_retries       IN    NUMBER   DEFAULT NULL,
   retry_delay       IN    NUMBER   DEFAULT NULL,
   retention_time    IN    NUMBER   DEFAULT NULL,
   auto_commit       IN    BOOLEAN  DEFAULT TRUE,
   comment           IN    VARCHAR2 DEFAULT NULL);

Parameters

Table 23-15 ALTER_QUEUE Procedure Parameters

Parameter Description

queue_name

Name of the queue that is to be altered

max_retries

Limits the number of times a dequeue with REMOVE mode can be attempted on a message. The maximum value of max_retries is 2**31 -1.

A message is moved to an exception queue if RETRY_COUNT is greater than MAX_RETRIES. RETRY_COUNT is incremented when the application issues a rollback after executing the dequeue. If a dequeue transaction fails because the server process dies (including ALTER SYSTEM KILL SESSION) or SHUTDOWN ABORT on the instance, then RETRY_COUNT is not incremented.

Note that max_retries is supported for all single consumer queues and 8.1-compatible or higher multiconsumer queues but not for 8.0-compatible multiconsumer queues.

retry_delay

Delay time in seconds before this message is scheduled for processing again after an application rollback. The default is NULL, which means that the value will not be altered.

Note that retry_delay is supported for single consumer queues and 8.1-compatible or higher multiconsumer queues but not for 8.0-compatible multiconsumer queues.

retention_time

Retention time in seconds for which a message is retained in the queue table after being dequeued. The default is NULL, which means that the value will not be altered.

auto_commit

TRUE causes the current transaction, if any, to commit before the ALTER_QUEUE operation is carried out. The ALTER_QUEUE operation become persistent when the call returns. This is the default. FALSE means the operation is part of the current transaction and becomes persistent only when the caller enters a commit.

Caution: This parameter has been deprecated.

comment

User-specified description of the queue. This user comment is added to the queue catalog. The default value is NULL, which means that the value will not be changed.

23.4.6 ALTER_QUEUE_TABLE Procedure

This procedure alters the existing properties of a queue table.

Syntax

DBMS_AQADM.ALTER_QUEUE_TABLE (
   queue_table          IN   VARCHAR2, 
   comment              IN   VARCHAR2       DEFAULT NULL,
   primary_instance     IN   BINARY_INTEGER DEFAULT NULL, 
   secondary_instance   IN   BINARY_INTEGER DEFAULT NULL,
   replication_mode     IN   BINARY_INTEGER DEFAULT NULL);

Parameters

Table 23-16 ALTER_QUEUE_TABLE Procedure Parameters

Parameter Description

queue_table

Name of a queue table to be created.

comment

Modifies the user-specified description of the queue table. This user comment is added to the queue catalog. The default value is NULL which means that the value will not be changed.

primary_instance

This is the primary owner of the queue table. Queue monitor scheduling and propagation for the queues in the queue table will be done in this instance. The default value is NULL, which means that the current value will not be changed.

secondary_instance

The queue table fails over to the secondary instance if the primary instance is not available. The default value is NULL, which means that the current value will not be changed.

replication_mode

DBMS_AQADM.REPLICATION_MODE if queue is being altered to be in the Replication Mode. DBMS_AQADM.NONE if queue is being altered to not be replicated. The default value is NULL.

23.4.7 ALTER_SHARDED_QUEUE Procedure

This procedure provides user the ability to alter a sharded queue.

See Also:

Oracle® Database Advanced Queuing User's Guide for information about sharded queues

Syntax

PROCEDURE ALTER_SHARDED_QUEUE(
    queue_name             IN VARCHAR2,
    max_retries            IN NUMBER         DEFAULT NULL,
    comment                IN VARCHAR2       DEFAULT NULL,
    queue_properties       IN QUEUE_PROPS_T  DEFAULT NULL,
    replication_mode       IN BINARY_INTEGER DEFAULT NULL);

Parameters

Table 23-17 ALTER_SHARDED_QUEUE Procedure Parameters

Parameter Description

queue_name

This parameter specifies the name of the sharded queue. A maximum of 128 characters are allowed.

max_retries

The maximum number of retries allowed.

comment

The comment of the queue.

queue_properties

Properties such as Normal or Exception Queue, Retry delay, retention time, sort list and cache hint.

Refer to QUEUE_PROPS_T Typefor more information about queue_properties.

replication_mode

Reserved for future use. DBMS_AQADM.REPLICATION_MODE if queue is being altered to be in the Replication Mode or else DBMS_AQADM.NONE. Default is NULL.

23.4.8 ALTER_SUBSCRIBER Procedure

This procedure alters existing properties of a subscriber to a specified queue. Only the rule can be altered.

Syntax

DBMS_AQADM.ALTER_SUBSCRIBER (
   queue_name     IN    VARCHAR2,
   subscriber     IN    sys.aq$_agent,
   rule           IN    VARCHAR2
   transformation IN    VARCHAR2);

Parameters

Table 23-18 ALTER_SUBSCRIBER Procedure Parameters

Parameter Description

queue_name

Name of the queue.

subscriber

Agent on whose behalf the subscription is being altered. See "AQ__AGENT Type".

rule

A conditional expression based on the message properties, the message data properties and PL/SQL functions. The rule parameter cannot exceed 4000 characters. To eliminate the rule, set the rule parameter to NULL.

transformation

Specifies a transformation that will be applied when this subscriber dequeues the message. The source type of the transformation must match the type of the queue. If the subscriber is remote, then the transformation is applied before propagation to the remote queue.

Usage Notes

This procedure alters both the rule and the transformation for the subscriber. If you want to retain the existing value for either of them, you must specify its old value. The current values for rule and transformation for a subscriber can be obtained from the schema.AQ$queue_table_R and schema.AQ$queue_table_S views.

23.4.9 ALTER_TRANSACTIONAL_EVENT_QUEUE Procedure

This procedure provides user the ability to alter a TEQ queue.

See Also:

Oracle® Database Advanced Queuing User's Guide for information about TEQ queues

Syntax

PROCEDURE ALTER_TRANSACTIONAL_EVENT_QUEUE(
    queue_name             IN VARCHAR2,
    max_retries            IN NUMBER         DEFAULT NULL,
    comment                IN VARCHAR2       DEFAULT NULL,
    queue_properties       IN QUEUE_PROPS_T  DEFAULT NULL,
    replication_mode       IN BINARY_INTEGER DEFAULT NULL);

Parameters

Table 23-19 ALTER_TRANSACTIONAL_EVENT_QUEUE Procedure Parameters

Parameter Description

queue_name

This parameter specifies the name of the TEQ queue. A maximum of 128 characters are allowed.

max_retries

The maximum number of retries allowed.

comment

The comment of the queue.

queue_properties

Properties such as Normal or Exception Queue, Retry delay, retention time, sort list and cache hint.

Refer to QUEUE_PROPS_T Typefor more information about queue_properties.

replication_mode

Reserved for future use. DBMS_AQADM.REPLICATION_MODE if queue is being altered to be in the Replication Mode or else DBMS_AQADM.NONE. Default is NULL.

23.4.10 CREATE_AQ_AGENT Procedure

This procedure registers an agent for Oracle Database Advanced Queuing Internet access using HTTP/SMTP protocols. It is also used to create an Oracle Database Advanced Queuing agent to access secure queues.

Syntax

DBMS_AQADM.CREATE_AQ_AGENT (
  agent_name                IN VARCHAR2,
  certificate_location      IN VARCHAR2 DEFAULT NULL,
  enable_http               IN BOOLEAN DEFAULT FALSE,
  enable_smtp               IN BOOLEAN DEFAULT FALSE,
  enable_anyp               IN BOOLEAN DEFAULT FALSE )

Parameters

Table 23-20 CREATE_AQ_AGENT Procedure Parameters

Parameter Description

agent_name

Specifies the username of the Oracle Database Advanced Queuing Internet agent.

certification_location

Agent's certificate location in LDAP (default is NULL). If the agent is allowed to access Oracle Database Advanced Queuing through SMTP, then its certificate must be registered in LDAP. For access through HTTP, the certificate location is not required.

enable_http

TRUE means the agent can access Oracle Database Advanced Queuing through HTTP. FALSE means the agent cannot access Oracle Database Advanced Queuing through HTTP.

enable_smtp

TRUE means the agent can access Oracle Database Advanced Queuing through SMTP (e-mail). FALSE means the agent cannot access Oracle Database Advanced Queuing through SMTP.

enable_anyp

TRUE means the agent can access Oracle Database Advanced Queuing through any protocol (HTTP or SMTP).

Usage Notes

The SYS.AQ$INTERNET_USERS view has a list of all Oracle Database Advanced Queuing Internet agents.

23.4.11 CREATE_NP_QUEUE Procedure

This procedure creates a nonpersistent RAW queue.

Note:

Nonpersistent queues are deprecated as of Release 10gR2. Oracle recommends using buffered messaging.

Syntax

DBMS_AQADM.CREATE_NP_QUEUE ( 
   queue_name              IN        VARCHAR2, 
   multiple_consumers      IN        BOOLEAN  DEFAULT FALSE, 
   comment                 IN        VARCHAR2 DEFAULT NULL);

Parameters

Table 23-21 CREATE_NP_QUEUE Procedure Parameters

Parameter Description

queue_name

Name of the nonpersistent queue that is to be created. The name must be unique within a schema and must follow object name guidelines in Oracle Database SQL Language Reference.

multiple_consumers

FALSE means queues created in the table can only have one consumer for each message. This is the default. TRUE means queues created in the table can have multiple consumers for each message.

Note that this parameter is distinguished at the queue level, because a nonpersistent queue does not inherit this characteristic from any user-created queue table.

comment

User-specified description of the queue. This user comment is added to the queue catalog.

Usage Notes

The queue may be either single-consumer or multiconsumer queue. All queue names must be unique within a schema. The queues are created in a 8.1-compatible or higher system-created queue table (AQ$_MEM_SC or AQ$_MEM_MC) in the same schema as that specified by the queue name.

If the queue name does not specify a schema name, the queue is created in the login user's schema. After a queue is created with CREATE_NP_QUEUE, it can be enabled by calling START_QUEUE. By default, the queue is created with both enqueue and dequeue disabled.

You cannot dequeue from a nonpersistent queue. The only way to retrieve a message from a nonpersistent queue is by using the OCI notification mechanism. You cannot invoke the LISTEN call on a nonpersistent queue.

23.4.12 CREATE_QUEUE Procedure

This procedure creates a queue in the specified queue table.

Syntax

DBMS_AQADM.CREATE_QUEUE (
   queue_name          IN       VARCHAR2,
   queue_table         IN       VARCHAR2,
   queue_type          IN       BINARY_INTEGER DEFAULT NORMAL_QUEUE,
   max_retries         IN       NUMBER         DEFAULT NULL,
   retry_delay         IN       NUMBER         DEFAULT 0,
   retention_time      IN       NUMBER         DEFAULT 0,
   dependency_tracking IN       BOOLEAN        DEFAULT FALSE,
   comment             IN       VARCHAR2       DEFAULT NULL,
   auto_commit         IN       BOOLEAN        DEFAULT TRUE);

Parameters

Table 23-22 CREATE_QUEUE Procedure Parameters

Parameter Description

queue_name

Name of the queue that is to be created. The name must be unique within a schema and must follow object name guidelines in Oracle Database SQL Language Reference with regard to reserved characters.

queue_table

Name of the queue table that will contain the queue.

queue_type

Specifies whether the queue being created is an exception queue or a normal queue. NORMAL_QUEUE means the queue is a normal queue. This is the default. EXCEPTION_QUEUE means it is an exception queue. Only the dequeue operation is allowed on the exception queue.

max_retries

Limits the number of times a dequeue with the REMOVE mode can be attempted on a message. The maximum value of max_retries is 2**31 -1.

A message is moved to an exception queue if RETRY_COUNT is greater than MAX_RETRIES. RETRY_COUNT is incremented when the application issues a rollback after executing the dequeue. If a dequeue transaction fails because the server process dies (including ALTER SYSTEM KILL SESSION) or SHUTDOWN ABORT on the instance, then RETRY_COUNT is not incremented.

Note that max_retries is supported for all single consumer queues and 8.1-compatible or higher multiconsumer queues but not for 8.0-compatible multiconsumer queues.

retry_delay

Delay time, in seconds, before this message is scheduled for processing again after an application rollback.

The default is 0, which means the message can be retried as soon as possible. This parameter has no effect if max_retries is set to 0. Note that retry_delay is supported for single consumer queues and 8.1-compatible or higher multiconsumer queues but not for 8.0-compatible multiconsumer queues.

retention_time

Number of seconds for which a message is retained in the queue table after being dequeued from the queue. INFINITE means the message is retained forever. NUMBER is the number of seconds for which to retain the messages. The default is 0, no retention.

dependency_tracking

Reserved for future use. FALSE is the default. TRUE is not permitted in this release.

comment

User-specified description of the queue. This user comment is added to the queue catalog.

auto_commit

TRUE causes the current transaction, if any, to commit before the CREATE_QUEUE operation is carried out. The CREATE_QUEUE operation becomes persistent when the call returns. This is the default. FALSE means the operation is part of the current transaction and becomes persistent only when the caller enters a commit.

Caution: This parameter has been deprecated.

Usage Notes

All queue names must be unique within a schema. After a queue is created with CREATE_QUEUE, it can be enabled by calling START_QUEUE. By default, the queue is created with both enqueue and dequeue disabled.

23.4.13 CREATE_QUEUE_TABLE Procedure

This procedure creates a queue table for messages of a predefined type.

Syntax

DBMS_AQADM.CREATE_QUEUE_TABLE (
   queue_table          IN      VARCHAR2,
   queue_payload_type   IN      VARCHAR2,
   storage_clause       IN      VARCHAR2        DEFAULT NULL,
   sort_list            IN      VARCHAR2        DEFAULT NULL,
   multiple_consumers   IN      BOOLEAN         DEFAULT FALSE,
   message_grouping     IN      BINARY_INTEGER  DEFAULT NONE,
   comment              IN      VARCHAR2        DEFAULT NULL,
   auto_commit          IN      BOOLEAN         DEFAULT TRUE,
   primary_instance     IN      BINARY_INTEGER  DEFAULT 0, 
   secondary_instance   IN      BINARY_INTEGER  DEFAULT 0,
   compatible           IN      VARCHAR2        DEFAULT NULL,
   secure               IN      BOOLEAN         DEFAULT FALSE
   replication_mode     IN      BINARY_INTEGER  DEFAULT NONE);

Parameters

Table 23-23 CREATE_QUEUE_TABLE Procedure Parameters

Parameter Description

queue_table

Name of a queue table to be created

queue_payload_type

Type of the user data stored. See Type Name inDBMS_AQ Data Types for valid values for this parameter.

storage_clause

Storage parameter. The storage parameter is included in the CREATE TABLE statement when the queue table is created. The storage_clause argument can take any text that can be used in a standard CREATE TABLE storage_clause argument.The storage parameter can be made up of any combinations of the following parameters: PCTFREE, PCTUSED, INITRANS, MAXTRANS, TABLESPACE, LOB, and a table storage clause.

If a tablespace is not specified here, then the queue table and all its related objects are created in the default user tablespace. If a tablespace is specified here, then the queue table and all its related objects are created in the tablespace specified in the storage clause. See Oracle Database SQL Language Reference for the usage of these parameters.

sort_list

The columns to be used as the sort key in ascending order. This parameter has the following format:

'sort_column_1,sort_column_2'

The allowed column names are priority, enq_time, and commit_time.If both columns are specified, then sort_column_1 defines the most significant order.

After a queue table is created with a specific ordering mechanism, all queues in the queue table inherit the same defaults. The order of a queue table cannot be altered after the queue table has been created.

If no sort list is specified, then all the queues in this queue table are sorted by the enqueue time in ascending order. This order is equivalent to FIFO order.

Even with the default ordering defined, a dequeuer is allowed to choose a message to dequeue by specifying its msgid or correlation. msgid, correlation, and sequence_deviation take precedence over the default dequeueing order, if they are specified.

When commit_time is specified for the sort_list parameter the resulting queue table uses commit-time ordering.

See also "Priority and Ordering of Messages" in Oracle Database Advanced Queuing User's Guide for information about message ordering in Oracle Database Advanced Queuing.

multiple_consumers

FALSE means queues created in the table can only have one consumer for each message. This is the default. TRUE means queues created in the table can have multiple consumers for each message.

message_grouping

Message grouping behavior for queues created in the table. NONE means each message is treated individually. TRANSACTIONAL means messages enqueued as part of one transaction are considered part of the same group and can be dequeued as a group of related messages.

comment

User-specified description of the queue table. This user comment is added to the queue catalog.

auto_commit

TRUE causes the current transaction, if any, to commit before the CREATE_QUEUE_TABLE operation is carried out. The CREATE_QUEUE_TABLE operation becomes persistent when the call returns. This is the default. FALSE means the operation is part of the current transaction and becomes persistent only when the caller enters a commit.

Note: This parameter has been deprecated.

primary_instance

The primary owner of the queue table. Queue monitor scheduling and propagation for the queues in the queue table are done in this instance.

The default value for primary instance is 0, which means queue monitor scheduling and propagation will be done in any available instance.

secondary_instance

The queue table fails over to the secondary instance if the primary instance is not available. The default value is 0, which means that the queue table will fail over to any available instance.

compatible

The lowest database version with which the queue is compatible. Currently the possible values are either 8.0, 8.1, or 10.0. If the database is in 10.1-compatible mode, the default value is 10.0. If the database is in 8.1-compatible or 9.2-compatible mode, the default value is 8.1. If the database is in 8.0 compatible mode, the default value is 8.0.

secure

This parameter must be set to TRUE if you want to use the queue table for secure queues. Secure queues are queues for which AQ agents must be associated explicitly with one or more database users who can perform queue operations, such as enqueue and dequeue. The owner of a secure queue can perform all queue operations on the queue, but other users cannot perform queue operations on a secure queue, unless they are configured as secure queue users.

replication_mode

DBMS_AQADM.REPLICATION_MODE if queue is being created in the Replication Mode or else DBMS_AQADM.NONE. Default is DBMS_AQADM.NONE.

Usage Notes

The sort keys for dequeue ordering, if any, must be defined at table creation time. The following objects are created at this time:

  • aq$_queue_table_name_e, a default exception queue associated with the queue table

  • aq$queue_table_name, a read-only view, which is used by Oracle Database Advanced Queuing applications for querying queue data

  • aq$_queue_table_name_t, an index (or an index organized table (IOT) in the case of multiple consumer queues) for the queue monitor operations

  • aq$_queue_table_name_i, an index (or an index organized table in the case of multiple consumer queues) for dequeue operations

For 8.1-compatible or higher queue tables, the following index-organized tables are created:

  • aq$_queue_table_name_s, a table for storing information about the subscribers

  • aq$_queue_table_name_r, a table for storing information about rules on subscriptions

aq$_queue_table_name_h, an index-organized table for storing the dequeue history data

CLOB, BLOB, and BFILE are valid attributes for Oracle Database Advanced Queuing object type payloads. However, only CLOB and BLOB can be propagated using Oracle Database Advanced Queuing propagation in Oracle8i release 8.1.5 or later. See the Oracle Database Advanced Queuing User's Guide for more information.

The default value of the compatible parameter depends on the database compatibility mode in the init.ora. If the database is in 10.1-compatible mode, the default value is 10.0. If the database is in 8.1-compatible or 9.2-compatible mode, the default value is 8.1. If the database is in 8.0 compatible mode, the default value is 8.0

You can specify and modify the primary_instance and secondary_instance only in 8.1-compatible or higher mode. You cannot specify a secondary instance unless there is a primary instance.

23.4.14 CREATE_SHARDED_QUEUE Procedure

The CREATE_SHARDED_QUEUE API creates a queue and its queue table as appropriate for a sharded queue. This API cannot be used to create unsharded queues. Sharded queues must be created using this single integrated API that will automatically set AQ properties as needed

Starting with Oracle Database 20c, the CREATE_SHARDED_QUEUE procedure is deprecated and will be desupported in a future release. Use the CREATE_TRANSACTIONAL_EVENT_QUEUE Procedure procedure instead.

Sharded queues may be either a single consumer or a multi-consumer queue.

Syntax

PROCEDURE CREATE_SHARDED_QUEUE (
	queue_name             IN VARCHAR2,
	storage_clause         IN VARCHAR2       DEFAULT NULL,
	multiple_consumers     IN BOOLEAN        DEFAULT FALSE,
	max_retries            IN NUMBER         DEFAULT NULL,
	comment                IN VARCHAR2       DEFAULT NULL, 
	queue_payload_type     IN VARCHAR2       DEFAULT JMS_TYPE,
	queue_properties       IN QUEUE_PROPS_T  DEFAULT NULL,
	replication_mode       IN BINARY_INTEGER DEFAULT NONE,
	queue_type		IN BINARY_INTEGER DEFAULT SHARDED_QUEUE,
	squeue_ver             IN BINARY_INTEGER DEFAULT SQ); 

Parameters

Table 23-24 CREATE_SHARDED_QUEUE Procedure Parameters

Parameter Description

queue_name

This required parameter specifies the name of the new queue. Maximum of 128 characters allowed.

storage_clause

The storage parameter is included in the CREATE TABLE statement when the queue table is created. The storage_clause argument can take any text that can be used in a standard CREATE TABLE storage_clause argument. The storage parameter can be made up of any combinations of the following parameters: PCTFREE, PCTUSED, INITRANS, MAXTRANS, TABLESPACE, LOB, and a table storage clause.

If a tablespace is not specified here, then the queue table and all its related objects are created in the default user tablespace. If a tablespace is specified here, then the queue table and all its related objects are created in the tablespace specified in the storage clause. See Oracle Database SQL Language Reference for the usage of these parameters.

multiple_consumers

FALSE means queues can only have one consumer for each message. This is the default. TRUE means queues created in the table can have multiple consumers for each message.

max_retries

This optional parameter limits the number of times that a dequeue can reattempted on a message after a failure. The maximum value of max_retries is 2**31 -1. After the retry limit has been exceeded, the message will be purged from the queue. RETRY_COUNT is incremented when the application issues a rollback after executing the dequeue. If a dequeue transaction fails because the server process dies (including ALTER SYSTEM KILL SESSION) or SHUTDOWN ABORT on the instance, then RETRY_COUNT is not incremented.

comment

This optional parameter is a user-specified description of the queue table. This user comment is added to the queue catalog.

queue_payload_type

Payload can be RAW, JSON, DBMS_AQADM.JMS_TYPE, or an object type. Default is DBMS_AQADM.JMS_TYPE.

See DBMS_AQ Data Types.

queue_properties

Properties such as Normal or Exception Queue, Retry delay, retention time, sort list and cache hint.

Refer to QUEUE_PROPS_T Typefor ore information about queue_properties.

replication_mode

Reserved for future use. DBMS_AQADM.REPLICATION_MODE if Queue is being created in the Replication Mode or else DBMS_AQADM.NONE. Default is DBMS_AQADM.NONE.

queue_kind

This parameter specifies the queue type. The following types are:

CLASSIC_QUEUE CONSTANT BINARY_INTEGER := 0;

SHARDED_QUEUE CONSTANT BINARY_INTEGER := 1;

TRANSACTIONAL_EVENT_QUEUE CONSTANT BINARY_INTEGER := 2;

The default value is SHARDED_QUEUE.

squeue_ver

The sharded queue phase/version.

SQ CONSTANT BINARY_INTEGER := 0;

TEQ CONSTANT BINARY_INTEGER := 1;

23.4.15 CREATE_EXCEPTION_QUEUE Procedure

The CREATE_EXCEPTION_QUEUE API creates an exception queue for a sharded queue.

Syntax

PROCEDURE CREATE_EXCEPTION_QUEUE(
    sharded_queue_name     IN VARCHAR2,
    exception_queue_name   IN VARCHAR2 DEFAULT NULL
    );

Parameters

Table 23-25 CREATE_EXCEPTION_QUEUE Procedure Parameters

Parameter Description

sharded_queue_name

The name of the sharded queue.

exception_queue_name

The name of the exception queue.

23.4.16 CREATE_EQ EXCEPTION_QUEUE Procedure

The CREATE_EQ_EXCEPTION_QUEUE API creates an exception queue for a TEQ queue.

Syntax

PROCEDURE CREATE_EQ_EXCEPTION_QUEUE(
    teq_queue_name     IN VARCHAR2,
    exception_queue_name   IN VARCHAR2 DEFAULT NULL
    );

Parameters

Table 23-26 CREATE_EQ_EXCEPTION_QUEUE Procedure Parameters

Parameter Description

teq_queue_name

The name of the TEQ queue.

exception_queue_name

The name of the exception queue.

23.4.17 CREATE_TRANSACTIONAL_EVENT_QUEUE Procedure

The CREATE_TRANSACTIONAL_EVENT_QUEUE API creates a queue and its queue table as appropriate for a Transactional Event Queue (TEQ). This API cannot be used to create AQ queues. TEQs must be created using this single integrated API that will automatically set AQ properties as needed.

TEQs may be either a single consumer or a multi-consumer queue.

Syntax

PROCEDURE CREATE_TRANSACTIONAL_EVENT_QUEUE (
	queue_name             IN VARCHAR2,
	storage_clause         IN VARCHAR2       DEFAULT NULL,
	multiple_consumers     IN BOOLEAN        DEFAULT FALSE,
	max_retries            IN NUMBER         DEFAULT NULL,
	comment                IN VARCHAR2       DEFAULT NULL, 
	queue_payload_type     IN VARCHAR2       DEFAULT JMS_TYPE,
	queue_properties       IN QUEUE_PROPS_T  DEFAULT NULL,
	replication_mode       IN BINARY_INTEGER DEFAULT NONE); 

Parameters

Table 23-27 CREATE_TRANSACTIONAL_EVENT_QUEUE Procedure Parameters

Parameter Description

queue_name

This required parameter specifies the name of the new queue. Maximum of 128 characters allowed.

storage_clause

The storage parameter is included in the CREATE TABLE statement when the queue table is created. The storage_clause argument can take any text that can be used in a standard CREATE TABLE storage_clause argument. The storage parameter can be made up of any combinations of the following parameters: PCTFREE, PCTUSED, INITRANS, MAXTRANS, TABLESPACE, LOB, and a table storage clause.

If a tablespace is not specified here, then the queue table and all its related objects are created in the default user tablespace. If a tablespace is specified here, then the queue table and all its related objects are created in the tablespace specified in the storage clause. See Oracle Database SQL Language Reference for the usage of these parameters.

multiple_consumers

FALSE means queues can only have one consumer for each message. This is the default. TRUE means queues created in the table can have multiple consumers for each message.

max_retries

This optional parameter limits the number of times that a dequeue can reattempted on a message after a failure. The maximum value of max_retries is 2**31 -1. After the retry limit has been exceeded, the message will be purged from the queue. RETRY_COUNT is incremented when the application issues a rollback after executing the dequeue. If a dequeue transaction fails because the server process dies (including ALTER SYSTEM KILL SESSION) or SHUTDOWN ABORT on the instance, then RETRY_COUNT is not incremented.

comment

This optional parameter is a user-specified description of the queue table. This user comment is added to the queue catalog.

queue_payload_type

Payload can be RAW, JSON, DBMS_AQADM.JMS_TYPE, or an object type. Default is DBMS_AQADM.JMS_TYPE.

See DBMS_AQ Data Types.

queue_properties

Properties such as Normal or Exception Queue, Retry delay, retention time, sort list and cache hint.

Refer to QUEUE_PROPS_T Typefor ore information about queue_properties.

replication_mode

Reserved for future use. DBMS_AQADM.REPLICATION_MODE if Queue is being created in the Replication Mode or else DBMS_AQADM.NONE. Default is DBMS_AQADM.NONE.

23.4.18 DEL_ALIAS_FROM_LDAP Procedure

This procedure drops an alias for a queue, agent, or JMS ConnectionFactory in LDAP.

Syntax

DBMS_AQADM.DEL_ALIAS_FROM_LDAP(
   alias IN VARCHAR2);

Parameters

Table 23-28 DEL_ALIAS_FROM_LDAP Procedure Parameters

Parameter Description

alias

The alias to be removed.

23.4.19 DISABLE_DB_ACCESS Procedure

This procedure revokes the privileges of a specific database user from an Oracle Database Advanced Queuing Internet agent.

Syntax

DBMS_AQADM.DISABLE_DB_ACCESS (
  agent_name                IN VARCHAR2,
  db_username               IN VARCHAR2)

Parameters

Table 23-29 DISABLE_DB_ACCESS Procedure Parameters

Parameter Description

agent_name

Specifies the username of the Oracle Database Advanced Queuing Internet agent.

db_username

Specifies the database user whose privileges are to be revoked from the Oracle Database Advanced Queuing Internet agent.

Usage Notes

The Oracle Database Advanced Queuing Internet agent should have been previously granted those privileges using the ENABLE_DB_ACCESS Procedure.

23.4.20 DISABLE_PROPAGATION_SCHEDULE Procedure

This procedure disables a propagation schedule.

Syntax

DBMS_AQADM.DISABLE_PROPAGATION_SCHEDULE ( 
   queue_name            IN   VARCHAR2, 
   destination           IN   VARCHAR2 DEFAULT NULL,
   destination_queue  IN  VARCHAR2 DEFAULT NULL);

Parameters

Table 23-30 DISABLE_PROPAGATION_SCHEDULE Procedure Parameters

Parameter Description

queue_name

Name of the source queue whose messages are to be propagated, including the schema name. If the schema name is not specified, then it defaults to the schema name of the user.

destination

Destination database link. Messages in the source queue for recipients at this destination are propagated. If it is NULL, then the destination is the local database and messages are propagated to other queues in the local database. The length of this field is currently limited to 128 bytes, and if the name is not fully qualified, then the default domain name is used.

destination_queue

Name of the target queue to which messages are to be propagated in the form of a dblink

23.4.21 DROP_AQ_AGENT Procedure

This procedure drops an agent that was previously registered for Oracle Database Advanced Queuing Internet access.

Syntax

DBMS_AQADM.DROP_AQ_AGENT (
  agent_name                IN VARCHAR2)

Parameters

Table 23-31 DROP_AQ_AGENT Procedure Parameters

Parameter Description

agent_name

Specifies the username of the Oracle Database Advanced Queuing Internet agent

23.4.22 DROP_QUEUE Procedure

This procedure drops an existing queue.

Syntax

DBMS_AQADM.DROP_QUEUE (
   queue_name        IN    VARCHAR2,
   auto_commit       IN    BOOLEAN DEFAULT TRUE);

Parameters

Table 23-32 DROP_QUEUE Procedure Parameters

Parameter Description

queue_name

Name of the queue that is to be dropped.

auto_commit

TRUE causes the current transaction, if any, to commit before the DROP_QUEUE operation is carried out. The DROP_QUEUE operation becomes persistent when the call returns. This is the default. FALSE means the operation is part of the current transaction and becomes persistent only when the caller enters a commit.

Caution: This parameter has been deprecated.

Usage Notes

DROP_QUEUE is not allowed unless STOP_QUEUE has been called to disable the queue for both enqueuing and dequeuing. All the queue data is deleted as part of the drop operation.

23.4.23 DROP_QUEUE_TABLE Procedure

This procedure drops an existing queue table.

Syntax

DBMS_AQADM.DROP_QUEUE_TABLE (
   queue_table       IN    VARCHAR2,
   force             IN    BOOLEAN DEFAULT FALSE,
   auto_commit       IN    BOOLEAN DEFAULT TRUE);

Parameters

Table 23-33 DROP_QUEUE_TABLE Procedure Parameters

Parameter Description

queue_table

Name of a queue table to be dropped.

force

FALSE means the operation does not succeed if there are any queues in the table. This is the default. TRUE means all queues in the table are stopped and dropped automatically.

auto_commit

TRUE causes the current transaction, if any, to commit before the DROP_QUEUE_TABLE operation is carried out. The DROP_QUEUE_TABLE operation becomes persistent when the call returns. This is the default. FALSE means the operation is part of the current transaction and becomes persistent only when the caller enters a commit.

Caution: This parameter has been deprecated.

Usage Notes

All the queues in a queue table must be stopped and dropped before the queue table can be dropped. You must do this explicitly unless the force option is used, in which case this is done automatically.

23.4.24 DROP_SHARDED_QUEUE Procedure

This procedure drops an existing sharded queue from the database queuing system.

You must stop the queue before calling DROP_SHARDED_QUEUE. User must stop the queue explicitly if force is set to FALSE before calling DROP_SHARDED_QUEUE. If force is set to TRUE then queue will be stopped internally and then dropped.

Syntax

DBMS_AQADM.DROP_SHARDED_QUEUE( 
       queue_name IN VARCHAR2, 
       force      IN BOOLEAN DEFAULT FALSE )

Parameters

Table 23-34 DROP_SHARDED_QUEUE Procedure Parameters

Parameter Description

queue_name

This required parameter specifies the name of the sharded queue.

force

The sharded queue is dropped even if the queue is not stopped.

23.4.25 DROP_TRANSACTIONAL_EVENT_QUEUE Procedure

This procedure drops an existing TEQ queue from the database queuing system.

You must stop the queue before calling DROP_TRANSACTIONAL_EVENT_QUEUE. User must stop the queue explicitly if force is set to FALSE before calling DROP_TRANSACTIONAL_EVENT_QUEUE. If force is set to TRUE then queue will be stopped internally and then dropped.

Syntax

DBMS_AQADM.DROP_TRANSACTIONAL_EVENT_QUEUE( 
       queue_name IN VARCHAR2, 
       force      IN BOOLEAN DEFAULT FALSE )

Parameters

Table 23-35 DROP_TRANSACTIONAL_EVENT_QUEUE Procedure Parameters

Parameter Description

queue_name

This required parameter specifies the name of the TEQ queue.

force

The TEQ queue is dropped even if the queue is not stopped.

23.4.26 ENABLE_DB_ACCESS Procedure

This procedure grants an Oracle Database Advanced Queuing Internet agent the privileges of a specific database user.

Syntax

DBMS_AQADM.ENABLE_DB_ACCESS (
  agent_name                IN VARCHAR2,
  db_username               IN VARCHAR2)

Parameters

Table 23-36 ENABLE_DB_ACCESS Procedure Parameters

Parameter Description

agent_name

Specifies the username of the Oracle Database Advanced Queuing Internet agent.

db_username

Specified the database user whose privileges are to be granted to the Oracle Database Advanced Queuing Internet agent.

Usage Notes

The Oracle Database Advanced Queuing Internet agent should have been previously created using the CREATE_AQ_AGENT Procedure.

For secure queues, the sender and receiver agent of the message must be mapped to the database user performing the enqueue or dequeue operation.

The SYS.AQ$INTERNET_USERS view has a list of all Oracle Database Advanced Queuing Internet agents and the names of the database users whose privileges are granted to them.

23.4.27 ENABLE_JMS_TYPES Procedure

Enqueue JMS types and XML types.

Syntax

DBMS_AQADM.ENABLE_JMS_TYPES (
   queue_table   IN   VARCHAR2);

Parameters

Table 23-37 ENABLE_JMS_TYPES Procedure Parameters

Parameter Description

queue_table

Specifies name of the queue table to be enabled for JMS and XML types.

23.4.28 ENABLE_PROPAGATION_SCHEDULE Procedure

This procedure enables a previously disabled propagation schedule.

Syntax

DBMS_AQADM.ENABLE_PROPAGATION_SCHEDULE ( 
   queue_name         IN   VARCHAR2, 
   destination        IN   VARCHAR2 DEFAULT NULL,
   destination_queue  IN   VARCHAR2  DEFAULT NULL);

Parameters

Table 23-38 ENABLE_PROPAGATION_SCHEDULE Procedure Parameters

Parameter Description

queue_name

Name of the source queue whose messages are to be propagated, including the schema name. If the schema name is not specified, then it defaults to the schema name of the user.

destination

Destination database link. Messages in the source queue for recipients at this destination are propagated. If it is NULL, then the destination is the local database and messages are propagated to other queues in the local database. The length of this field is currently limited to 128 bytes, and if the name is not fully qualified, then the default domain name is used.

destination_queue

Name of the target queue to which messages are to be propagated in the form of a dblink

23.4.29 GET_MAX_STREAMS_POOL Procedure

This procedure retrieves the value of Oracle Database Advanced Queuing maximum streams pool memory limit.

Syntax

DBMS_AQADM.GET_MAX_STREAMS_POOL (
   value     OUT      NUMBER);

Parameters

Table 23-39 GET_MAX_STREAMS_POOL Procedure Parameter

Parameter Description

value

Value in megabytes.

23.4.30 GET_MIN_STREAMS_POOL Procedure

This procedure retrieves the value of Oracle Database Advanced Queuing minimum streams pool memory limit.

Syntax

DBMS_AQADM.GET_MIN_STREAMS_POOL (
   value     OUT      NUMBER);

Parameters

Table 23-40 GET_MIN_STREAMS_POOL Procedure Parameter

Parameter Description

value

Value in megabytes.

23.4.31 GET_QUEUE_PARAMETER Procedure

This procedure allows user to get different parameters for sharded queues at queue or database level.

For database level the queue_name should be NULL. Note that queue overrides database level parameter values.

See Also:

Oracle® Database Advanced Queuing User's Guide for information about sharded queues

Syntax

PROCEDURE  GET_QUEUE_PARAMETER(
    queue_name          IN VARCHAR2,
    param_name          IN VARCHAR2,
    param_value         OUT NUMBER);

Parameters

Table 23-41 GET_QUEUE_PARAMETER Procedure Parameters

Parameter Description

queue_name

The name of the sharded queue.

param_name

The name of the parameter. Table 23-42 and Table 23-43 describe the valid parameter names.

param_value

The value of the parameter.

Table 23-42 Sharded queue parameters

Parameter Name Scope Allowed Values Description

SHARD_NUM

Queue level

[1, UB4MAXVAL]

Maximum number of shards allowed for the queue.

KEY_BASED_ENQUEUE

Queue level

[0,1]

When set, the shard to which a message gets enqueued is determined by the key value specified in the message. Refer to key-based sharding (link) for more details. This parameter cannot be unset once set.

When this parameter is not set (default), a session is bound to a shard at the time of first enqueue to the queue. All messages enqueued by the session will go to the same shard to which the session is bound.

STICKY_DEQUEUE

Queue level

[0,1]

When set, dequeue session sticks to a shard in the queue. A session is bound to a shard on first dequeue from the queue. All messages dequeued by the session come from the same shard to which it is bound. This parameter cannot be unset once set.

When this parameter is not set, messages dequeued by a session can spread across multiple shards of the queue.

Table 23-43 Key-based Parameters

Parameter Name Scope Description

AQ$KEY_TO_SHARD_MAP

Queue level

Shard number to which a given key is mapped. When key-based sharding is enabled, this parameter is used to establish mapping between a key and a shard number or retrieve the shard number to which given key is mapped.

AQ$GET_KEY_SHARD_INST

Queue level

Instance number that owns the shard to which a given key is mapped. Applicable only when key-based sharding is enabled. It is a read-only parameter.

Example 23-1 Key to shard mapping

Users can explicitly map a new key to an existing shard or to a new shard.

To map a key value 'RED' to a shard with id 0 for queue named MY_SHQ1, submit the following:

execute
        dbms_aqadm.set_queue_paramter('MY_SHQ1',  'AQ$KEY_TO_SHARD_MAP=RED', 0);

If a key is being enqueued which has not been explicitly mapped to a shard, then one of the shards is chosen at random and mapped to that key permanently. Once a key is mapped to shard, the mapping cannot be changed.

To get the shard identifier for a key which is mapped already, submit the following:

declare
  pval number;
begin
  dbms_aqadm.get_queue_parameter('MY_SHQ1', 'AQ$GET_KEY_SHARD=RED', pval);
  dbms_output.put_line('The key RED is mapped to shard id ' || pval);
END;
/

Example 23-2 Key to instance mapping

User sharding performs best when cross instance enqueues are not involved. To know the instance where a key can be enqueued without any cross instance enqueue, submit the following:

declare  
  pval number;
begin 
  dbms_aqadm.get_queue_parameter('MY_SHQ1', 'AQ$GET_KEY_SHARD_INST=RED', pval); 
  dbms_output.put_line('The key RED is owned by instance id ' || pval);
END;
/

23.4.32 GET_WATERMARK Procedure

This procedure retrieves the value of watermark set by SET_WATERMARK.

Syntax

DBMS_AQADM.GET_WATERMARK (
   wmvalue     IN      NUMBER);

Parameters

Table 23-44 GET_WATERMARK Procedure Parameter

Parameter Description

wmvalue

Watermark value in megabytes.

23.4.33 GRANT_QUEUE_PRIVILEGE Procedure

This procedure grants privileges on a queue to users and roles. The privileges are ENQUEUE or DEQUEUE. Initially, only the queue table owner can use this procedure to grant privileges on the queues.

Syntax

DBMS_AQADM.GRANT_QUEUE_PRIVILEGE (
   privilege        IN    VARCHAR2,
   queue_name       IN    VARCHAR2,
   grantee          IN    VARCHAR2,
   grant_option     IN    BOOLEAN := FALSE);

Parameters

Table 23-45 GRANT_QUEUE_PRIVILEGE Procedure Parameters

Parameter Description

privilege

The Oracle Database Advanced Queuing queue privilege to grant. The options are ENQUEUE, DEQUEUE, and ALL. ALL means both ENQUEUE and DEQUEUE.

queue_name

Name of the queue.

grantee

Grantee(s). The grantee(s) can be a user, a role, or the PUBLIC role.

grant_option

Specifies if the access privilege is granted with the GRANT option or not. If the privilege is granted with the GRANT option, then the grantee is allowed to use this procedure to grant the access privilege to other users or roles, regardless of the ownership of the queue table. The default is FALSE.

23.4.34 GRANT_SYSTEM_PRIVILEGE Procedure

This procedure grants Oracle Database Advanced Queuing system privileges to users and roles.

The privileges are ENQUEUE_ANY, DEQUEUE_ANY, and MANAGE_ANY. Initially, only SYS and SYSTEM can use this procedure successfully.

Note:

Starting from Oracle Database 12c Release 2, MANAGE_ANY, ENQUEUE_ANY, and DEQUEUE_ANY privileges will not allow access to SYS owned queues by users other than SYS.

Syntax

DBMS_AQADM.GRANT_SYSTEM_PRIVILEGE (
   privilege         IN    VARCHAR2,
   grantee           IN    VARCHAR2,
   admin_option      IN    BOOLEAN := FALSE);

Parameters

Table 23-46 GRANT_SYSTEM_PRIVILEGE Procedure Parameters

Parameter Description

privilege

The Oracle Database Advanced Queuing system privilege to grant. The options are ENQUEUE_ANY, DEQUEUE_ANY, and MANAGE_ANY. ENQUEUE_ANY means users granted this privilege are allowed to enqueue messages to any queues in the database. DEQUEUE_ANY means users granted this privilege are allowed to dequeue messages from any queues in the database. MANAGE_ANY means users granted this privilege are allowed to run DBMS_AQADM calls on any schemas in the database.

Note:

Starting from Oracle Database 12c Release 2, MANAGE_ANY, ENQUEUE_ANY, and DEQUEUE_ANY privileges will not allow access to SYS owned queues by users other than SYS.

grantee

Grantee(s). The grantee(s) can be a user, a role, or the PUBLIC role.

admin_option

Specifies if the system privilege is granted with the ADMIN option or not.

If the privilege is granted with the ADMIN option, then the grantee is allowed to use this procedure to grant the system privilege to other users or roles. The default is FALSE.

23.4.35 MIGRATE_QUEUE_TABLE Procedure

This procedure upgrades an 8.0-compatible queue table to an 8.1-compatible or higher queue table, or downgrades an 8.1-compatible or higher queue table to an 8.0-compatible queue table.

Syntax

DBMS_AQADM.MIGRATE_QUEUE_TABLE (
   queue_table   IN   VARCHAR2,
   compatible    IN   VARCHAR2);

Parameters

Table 23-47 MIGRATE_QUEUE_TABLE Procedure Parameters

Parameter Description

queue_table

Specifies name of the queue table to be migrated.

compatible

Set this to 8.1 to upgrade an 8.0-compatible queue table, or set this to 8.0 to downgrade an 8.1-compatible queue table.

23.4.36 PURGE_QUEUE_TABLE Procedure

This procedure purges messages from queue tables. You can perform various purge operations on both single-consumer and multiconsumer queue tables for persistent and buffered messages.

Syntax

DBMS_AQADM.PURGE_QUEUE_TABLE(
   queue_table        IN   VARCHAR2,
   purge_condition    IN   VARCHAR2,
   purge_options      IN   aq$_purge_options_t);

where type aq$_purge_options_t is described in Oracle Database Advanced Queuing (AQ) Types.

Parameters

Table 23-48 PURGE_QUEUE_TABLE Procedure Parameters

Parameter Description

queue_table

Specifies the name of the queue table to be purged.

purge_condition

Specifies the purge condition to use when purging the queue table. The purge condition must be in the format of a SQL WHERE clause, and it is case-sensitive. The condition is based on the columns of aq$queue_table_name view.

When specifying the purge_condition, qualify the column names in aq$queue_table_name view with qtview.

To purge all queues in a queue table, set purge_condition to either NULL (a bare null word, no quotes) or'' (two single quotes).

purge_options

Type aq$_purge_options_t contains a block parameter and a delivery_mode parameter.

  • If block is TRUE, then an exclusive lock on all the queues in the queue table is held while purging the queue table. This will cause concurrent enqueuers and dequeuers to block while the queue table is purged. The purge call always succeeds if block is TRUE. The default for block is FALSE. This will not block enqueuers and dequeuers, but it can cause the purge to fail with an error during high concurrency times.

  • delivery_mode is used to specify whether DBMS_AQADM.PERSISTENT, DBMS_AQADM.BUFFERED or DBMS_AQADM.PERSISTENT_OR_BUFFERED types of messages are to be purged. You cannot implement arbitrary purge conditions if buffered messages have to be purged.

Usage Notes

  • You an purge selected messages from the queue table by specifying a purge_condition. Table 23-48 describes these parameters. Messages can be enqueued to and dequeued from the queue table while the queue table is being purged.

  • A trace file is generated in the udump destination when you run this procedure. It details what the procedure is doing.

  • This procedure commits batches of messages in autonomous transactions. Several such autonomous transactions may get executed as a part of one purge_queue_table call depending on the number of messages in the queue table.

23.4.37 QUEUE_SUBSCRIBERS Function

This function returns the subscribers to an 8.0-compatible multiconsumer queue in the PL/SQL index by table collection type DBMS_AQADM.AQ$_subscriber_list_t.

Each element of the collection is of type sys.aq$_agent. This functionality is provided for 8.1-compatible queues by the AQ$queue_table_name_S view.

Syntax

DBMS_AQADM.QUEUE_SUBSCRIBERS (
   queue_name         IN         VARCHAR2);
RETURN aq$_subscriber_list_t IS

Parameters

Table 23-49 QUEUE_SUBSCRIBERS Function Parameters

Parameter Description

queue_name

Specifies the queue whose subscribers are to be printed.

23.4.38 REMOVE_SUBSCRIBER Procedure

This procedure removes a default subscriber from a queue. This operation takes effect immediately, and the containing transaction is committed. All references to the subscriber in existing messages are removed as part of the operation.

Syntax

DBMS_AQADM.REMOVE_SUBSCRIBER (
   queue_name         IN         VARCHAR2,
   subscriber         IN         sys.aq$_agent);

Parameters

Table 23-50 REMOVE_SUBSCRIBER Procedure Parameters

Parameter Description

queue_name

Name of the queue.

subscriber

Agent who is being removed. See AQ$_AGENT Type.

23.4.39 REVOKE_QUEUE_PRIVILEGE Procedure

This procedure revokes privileges on a queue from users and roles. The privileges are ENQUEUE or DEQUEUE.

Syntax

DBMS_AQADM.REVOKE_QUEUE_PRIVILEGE (
   privilege         IN      VARCHAR2,
   queue_name        IN      VARCHAR2,
   grantee           IN      VARCHAR2);

Parameters

Table 23-51 REVOKE_QUEUE_PRIVILEGE Procedure Parameters

Parameter Description

privilege

The Oracle Database Advanced Queuing queue privilege to revoke. The options are ENQUEUE, DEQUEUE, and ALL. ALL means both ENQUEUE and DEQUEUE.

queue_name

Name of the queue.

grantee

Grantee(s). The grantee(s) can be a user, a role, or the PUBLIC role. If the privilege has been propagated by the grantee through the GRANT option, then the propagated privilege is also revoked.

Usage Notes

To revoke a privilege, the revoker must be the original grantor of the privilege. The privileges propagated through the GRANT option are revoked if the grantor's privileges are revoked.

23.4.40 REVOKE_SYSTEM_PRIVILEGE Procedure

This procedure revokes Oracle Database Advanced Queuing system privileges from users and roles. The privileges are ENQUEUE_ANY, DEQUEUE_ANY and MANAGE_ANY. The ADMIN option for a system privilege cannot be selectively revoked. Starting from Oracle Database 12c Release 2, MANAGE_ANY, ENQUEUE_ANY, and DEQUEUE_ANY privileges will not allow access to SYS owned queues by users other than SYS.

Syntax

DBMS_AQADM.REVOKE_SYSTEM_PRIVILEGE (
   privilege         IN   VARCHAR2,
   grantee           IN   VARCHAR2);

Parameters

Table 23-52 REVOKE_SYSTEM_PRIVILEGE Procedure Parameters

Parameter Description

privilege

The Oracle Database Advanced Queuing system privilege to revoke. The options are ENQUEUE_ANY, DEQUEUE_ANY, and MANAGE_ANY. The ADMIN option for a system privilege cannot be selectively revoked.

Note:

Starting from Oracle Database 12c Release 2, MANAGE_ANY, ENQUEUE_ANY, and DEQUEUE_ANY privileges will not allow access to SYS owned queues by users other than SYS.

grantee

Grantee(s). The grantee(s) can be a user, a role, or the PUBLIC role.

23.4.41 SCHEDULE_PROPAGATION Procedure

This procedure schedules propagation of messages from a queue to a destination identified by a specific database link.

Syntax

DBMS_AQADM.SCHEDULE_PROPAGATION (
   queue_name          IN    VARCHAR2,
   destination         IN    VARCHAR2 DEFAULT NULL,
   start_time          IN    DATE     DEFAULT SYSDATE,
   duration            IN    NUMBER   DEFAULT NULL,
   next_time           IN    VARCHAR2 DEFAULT NULL,
   latency             IN    NUMBER   DEFAULT 60,
   destination_queue   IN    VARCHAR2 DEFAULT NULL);

Parameters

Table 23-53 SCHEDULE_PROPAGATION Procedure Parameters

Parameter Description

queue_name

Name of the source queue whose messages are to be propagated, including the schema name. If the schema name is not specified, then it defaults to the schema name of the administrative user.

destination

Destination database link. Messages in the source queue for recipients at this destination are propagated. If it is NULL, then the destination is the local database and messages are propagated to other queues in the local database. The length of this field is currently limited to 390 bytes, and if the name is not fully qualified, then the default domain name is used. The pattern schema.queue@dblink is used.

start_time

Initial start time for the propagation window for messages from the source queue to the destination.

duration

Duration of the propagation window in seconds. A NULL value means the propagation window is forever or until the propagation is unscheduled.

next_time

Date function to compute the start of the next propagation window from the end of the current window. If this value is NULL, then propagation is stopped at the end of the current window. For example, to start the window at the same time every day, next_time should be specified as SYSDATE + 1 - duration/86400.

latency

Maximum wait, in seconds, in the propagation window for a message to be propagated after it is enqueued.

For example, if the latency is 60 seconds and there are no messages to be propagated during the propagation window, then messages from that queue for the destination are not propagated for at least 60 more seconds.

It is at least 60 seconds before the queue is checked again for messages to be propagated for the specified destination. If the latency is 600, then the queue is not checked for 10 minutes, and if the latency is 0, then a job queue process will be waiting for messages to be enqueued for the destination. As soon as a message is enqueued, it is propagated.

destination_queue

Name of the target queue to which messages are to be propagated in the form of a dblink

Usage Notes

Messages may also be propagated to other queues in the same database by specifying a NULL destination. If a message has multiple recipients at the same destination in either the same or different queues, the message is propagated to all of them at the same time.

Oracle extensions for JMS such as JMS propagation and remote subscribers are not currently supported for sharded queues. Propagation between sharded and non-sharded queues is not supported

23.4.42 SET_QUEUE_PARAMETER Procedure

This procedure allows user to set different parameters for sharded queues at queue or database level. For database level the queue_name should be NULL. Note that queue overrides database level parameter values.

See Also:

Oracle® Database Advanced Queuing User's Guide for information about sharded queues

Syntax

  PROCEDURE  SET_QUEUE_PARAMETER(
    queue_name          IN VARCHAR2,
    param_name          IN VARCHAR2,
    param_value         IN NUMBER);

Parameters

Table 23-54 SET_QUEUE_PARAMETER Procedure Parameters

Parameter Description

queue_name

The name of the sharded queue.

param_name

The name of the parameter. Table 23-55 and Table 23-56 describe the valid parameter names.

param_value

The value of the parameter.

Table 23-55 Sharded queue parameters

Parameter Name Scope Allowed Values Description

SHARD_NUM

Queue level

[1, UB4MAXVAL]

Maximum number of shards allowed for the queue.

KEY_BASED_ENQUEUE

Queue level

[0,1]

When set, the shard to which a message gets enqueued is determined by the key value specified in the message. Refer to key-based sharding (link) for more details. This parameter cannot be unset once set.

When this parameter is not set (default), a session is bound to a shard at the time of first enqueue to the queue. All messages enqueued by the session will go to the same shard to which the session is bound.

STICKY_DEQUEUE

Queue level

[0,1]

When set, dequeue session sticks to a shard in the queue. A session is bound to a shard on first dequeue from the queue. All messages dequeued by the session come from the same shard to which it is bound. This parameter cannot be unset once set.

When this parameter is not set, messages dequeued by a session can spread across multiple shards of the queue.

Table 23-56 Key-based Parameters

Parameter Name Scope Description

AQ$KEY_TO_SHARD_MAP

Queue level

Shard number to which a given key is mapped. When key-based sharding is enabled, this parameter is used to establish mapping between a key and a shard number or retrieve the shard number to which given key is mapped.

AQ$GET_KEY_SHARD_INST

Queue level

Instance number that owns the shard to which a given key is mapped. Applicable only when key-based sharding is enabled. It is a read-only parameter.

Example 23-3 Create a sharded queue with key based enqueues

To create a sharded queue with key based enqueues (user sharding), the PL/SQL procedure DBMS_AQADM.SET_QUEUE_PARAMETER is called after CREATE_SHARDED_QUEUE.

execute
        sys.dbms_aqadm.create_sharded_queue(queue_name => 'MY_SHQ1');
execute
        dbms_aqadm.set_queue_parameter('MY_SHQ1', 'KEY_BASED_ENQUEUE', 1);

Example 23-4 Create a sharded queue with sticky dequeues

To create a sharded queue with key based enqueues (user sharding), the PL/SQL procedure DBMS_AQADM.SET_QUEUE_PARAMETER is called after CREATE_SHARDED_QUEUE.

execute
        sys.dbms_aqadm.create_sharded_queue(queue_name => 'MY_SHQ1');
execute
        dbms_aqadm.set_queue_parameter('MY_SHQ1', 'STICKY_DEQUEUE', 1);

Example 23-5 Setting or changing the number of shards

Once a queue is created, it can have a maximum of 5 shards by default. Applications can change the number of shards as needed using the PL/SQL procedure DBMS_AQADM.SET_QUEUE_PARAMETER.

execute
        dbms_aqadm.set_queue_parameter('MY_SHQ1', 'SHARD_NUM', 200);

Note:

Odd numbered shard identifiers are reserved for internal use. In the above example, the 200 shard identifiers used will be 0, 2, 4, …, 398.

23.4.43 SET_MAX_STREAMS_POOL Procedure

This procedure is used for Oracle Database Advanced Queuing to specify and limit maximum streams pool memory use.

Syntax

DBMS_AQADM.SET_MAX_STREAMS_POOL (
   value     IN      NUMBER);

Parameters

Table 23-57 SET_MAX_STREAMS_POOL Procedure Parameter

Parameter Description

value

Value in megabytes.

23.4.44 SET_MIN_STREAMS_POOL Procedure

This procedure is used for Oracle Database AQ to specify and limit minimum streams pool memory use.

Syntax

DBMS_AQADM.SET_MIN_STREAMS_POOL (
   value     IN      NUMBER);

Parameters

Table 23-58 SET_MIN_STREAMS_POOL Procedure Parameter

Parameter Description

value

Value in megabytes.

23.4.45 SET_WATERMARK Procedure

This procedure is used for Oracle Database Advanced Queuing notification to specify and limit memory use.

Syntax

DBMS_AQADM.SET_WATERMARK (
   wmvalue     IN      NUMBER);

Parameters

Table 23-59 SET_WATERMARK Procedure Parameter

Parameter Description

wmvalue

Watermark value in megabytes.

23.4.46 START_QUEUE Procedure

This procedure enables the specified queue for enqueuing or dequeuing.

Syntax

DBMS_AQADM.START_QUEUE ( 
   queue_name      IN     VARCHAR2,
   enqueue         IN     BOOLEAN DEFAULT TRUE,
   dequeue         IN     BOOLEAN DEFAULT TRUE);

Parameters

Table 23-60 START_QUEUE Procedure Parameters

Parameter Description

queue_name

Name of the queue to be enabled

enqueue

Specifies whether ENQUEUE should be enabled on this queue. TRUE means enable ENQUEUE. This is the default. FALSE means do not alter the current setting.

dequeue

Specifies whether DEQUEUE should be enabled on this queue. TRUE means enable DEQUEUE. This is the default. FALSE means do not alter the current setting.

Usage Notes

After creating a queue, the administrator must use START_QUEUE to enable the queue. The default is to enable it for both ENQUEUE and DEQUEUE. Only dequeue operations are allowed on an exception queue. This operation takes effect when the call completes and does not have any transactional characteristics.

23.4.47 STOP_QUEUE Procedure

This procedure disables enqueuing or dequeuing on the specified queue.

Syntax

DBMS_AQADM.STOP_QUEUE (   
   queue_name      IN   VARCHAR2,
   enqueue         IN   BOOLEAN DEFAULT TRUE,
   dequeue         IN   BOOLEAN DEFAULT TRUE,
   wait            IN   BOOLEAN DEFAULT TRUE,
   free_memory     IN   BOOLEAN DEFAULT FALSE);

Parameters

Table 23-61 STOP_QUEUE Procedure Parameters

Parameter Description

queue_name

Name of the queue to be disabled

enqueue

Specifies whether ENQUEUE should be disabled on this queue. TRUE means disable ENQUEUE. This is the default. FALSE means do not alter the current setting.

dequeue

Specifies whether DEQUEUE should be disabled on this queue. TRUE means disable DEQUEUE. This is the default. FALSE means do not alter the current setting.

wait

Specifies whether to wait for the completion of outstanding transactions. TRUE means wait if there are any outstanding transactions. In this state no new transactions are allowed to enqueue to or dequeue from this queue. FALSE means return immediately either with a success or an error.

free_memory

Specifies whether the queue should be stopped.

Usage Notes

By default, this call disables both ENQUEUE and DEQUEUE. A queue cannot be stopped if there are outstanding transactions against the queue. This operation takes effect when the call completes and does not have any transactional characteristics.

23.4.48 UNSCHEDULE_PROPAGATION Procedure

This procedure unschedules previously scheduled propagation of messages from a queue to a destination identified by a specific database link.

Syntax

DBMS_AQADM.UNSCHEDULE_PROPAGATION (
   queue_name         IN  VARCHAR2,
   destination        IN  VARCHAR2 DEFAULT NULL
   destination_queue  IN  VARCHAR2 DEFAULT NULL);

Parameters

Table 23-62 UNSCHEDULE_PROPAGATION Procedure Parameters

Parameter Description

queue_name

Name of the source queue whose messages are to be propagated, including the schema name. If the schema name is not specified, then it defaults to the schema name of the administrative user.

destination

Destination database link. Messages in the source queue for recipients at this destination are propagated. If it is NULL, then the destination is the local database and messages are propagated to other queues in the local database. The length of this field is currently limited to 128 bytes, and if the name is not fully qualified, then the default domain name is used.

destination_queue

Name of the target queue to which messages are to be propagated in the form of a dblink

23.4.49 UNSET_QUEUE_PARAMETER Procedure

This procedure allows user to unset different parameters for sharded queues at queue or database level.

For database level the queue_name should be NULL. Note that queue overrides database level parameter values.

See Also:

Oracle® Database Advanced Queuing User's Guide for information about sharded queues

Syntax

  PROCEDURE  UNSET_QUEUE_PARAMETER(
    queue_name          IN VARCHAR2,
    param_name          IN VARCHAR2);

Parameters

Table 23-63 UNSET_QUEUE_PARAMETER Procedure Parameters

Parameter Description

queue_name

The name of the sharded queue.

param_name

The name of the parameter. Table 23-64 and Table 23-65 describe the valid parameter names.

Table 23-64 Sharded queue parameters

Parameter Name Scope Allowed Values Description

SHARD_NUM

Queue level

[1, UB4MAXVAL]

Maximum number of shards allowed for the queue.

KEY_BASED_ENQUEUE

Queue level

[0,1]

When set, the shard to which a message gets enqueued is determined by the key value specified in the message. Refer to key-based sharding (link) for more details. This parameter cannot be unset once set.

When this parameter is not set (default), a session is bound to a shard at the time of first enqueue to the queue. All messages enqueued by the session will go to the same shard to which the session is bound.

STICKY_DEQUEUE

Queue level

[0,1]

When set, dequeue session sticks to a shard in the queue. A session is bound to a shard on first dequeue from the queue. All messages dequeued by the session come from the same shard to which it is bound. This parameter cannot be unset once set.

When this parameter is not set, messages dequeued by a session can spread across multiple shards of the queue.

Table 23-65 Key-based Parameters

Parameter Name Scope Description

AQ$KEY_TO_SHARD_MAP

Queue level

Shard number to which a given key is mapped. When key-based sharding is enabled, this parameter is used to establish mapping between a key and a shard number or retrieve the shard number to which given key is mapped.

AQ$GET_KEY_SHARD_INST

Queue level

Instance number that owns the shard to which a given key is mapped. Applicable only when key-based sharding is enabled. It is a read-only parameter.

23.4.50 VERIFY_QUEUE_TYPES Procedure

This procedure verifies that the source and destination queues have identical types.

The result of the verification is stored in the table sys.aq$_message_types, overwriting all previous output of this command.

Syntax

DBMS_AQADM.VERIFY_QUEUE_TYPES (
   src_queue_name    IN    VARCHAR2,
   dest_queue_name   IN    VARCHAR2,
   destination       IN    VARCHAR2 DEFAULT NULL,
   rc                OUT   BINARY_INTEGER);

Parameters

Table 23-66 VERIFY_QUEUE_TYPES Procedure Parameters

Parameter Description

src_queue_name

Name of the source queue whose messages are to be propagated, including the schema name. If the schema name is not specified, then it defaults to the schema name of the user.

dest_queue_name

Name of the destination queue where messages are to be propagated, including the schema name. If the schema name is not specified, then it defaults to the schema name of the user.

destination

Destination database link. Messages in the source queue for recipients at this destination are propagated. If it is NULL, then the destination is the local database and messages are propagated to other queues in the local database. The length of this field is currently limited to 128 bytes, and if the name is not fully qualified, then the default domain name is used.

rc

Return code for the result of the procedure. If there is no error, and if the source and destination queue types match, then the result is 1. If they do not match, then the result is 0. If an Oracle error is encountered, then it is returned in rc.

Note:

  • SYS.AQ$_MESSAGE_TYPES can have multiple entries for the same source queue, destination queue, and database link, but with different transformations.

  • VERIFY_QUEUE_TYPES check happens once per AQ propagation schedule and not for every propagated message send.

  • In case the payload of the queue is modified then the existing propagation schedule between source and destination queue needs to be dropped and recreated.