The DBMS_AQADM package provides procedures to manage Oracle Database Advanced Queuing (AQ) configuration and administration information.
This chapter contains the following topics:
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 12 c Release 2, MANAGE_ANY privilege will not allow access to SYS owned queues by users other than SYS .
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 12 c Release 2, ENQUEUE_ANY and DEQUEUE_ANY privileges will not allow access to SYS owned queues by users other than SYS .
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.
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.
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 24-1 Enumerated Types in the Administrative Interface
0 , 1 , 2 . INFINITE
NORMAL_QUEUE , EXCEPTION_QUEUE , NON_PERSISTENT_QUEUE
For more information on the Java classes and data structures used in both DBMS_AQ and DBMS_AQADM , see the DBMS_AQ package.
This section lists and describes the DBMS_AQADM subprogram groups.
This DBMS_AQADM package is made up of the following subprogram groups:
This section lists and describes the DBMS_AQADM Queue Table subprograms.
Table 24-2 Queue Table Subprograms
Alters the existing properties of a queue table
Creates a queue table for messages of a predefined type
Drops an existing queue table
A precondition for the enqueue of JMS types and XML types
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
Purges messages from queue tables
This sections lists and describes the DBMS_AQADM Privilege subprograms.
Table 24-3 Privilege Subprograms
Grants privileges on a queue to users and roles
Grants Oracle Database Advanced Queuing system privileges to users and roles
Revokes privileges on a queue from users and roles
Revokes Oracle Database Advanced Queuing system privileges from users and roles
This sections lists and describes the DBMS_AQADM Queue subprograms.
Table 24-4 Queue Subprograms
Alters existing properties of a queue
Creates a nonpersistent RAW queue
Creates a queue in the specified queue table
Creates a queue and its queue table for a sharded queue all together.
Drops an existing sharded queue from the database queuing system
Alters an sharded queue in the database queuing system
Creates an exception queue for a sharded queue
Drops an existing queue
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
Enables the specified queue for enqueuing or dequeuing
Disables enqueuing or dequeuing on the specified queue
This sections lists and describes the DBMS_AQADM Subscriber subprograms.
Table 24-5 Subscriber Subprograms
Adds a default subscriber to a queue
Alters existing properties of a subscriber to a specified queue
Removes a default subscriber from a queue
This section lists and describes the DBMS_AQADM propagation subprograms.
Table 24-6 Propagation Subprograms
Alters parameters for a propagation schedule
Disables a propagation schedule
Enables a previously disabled propagation schedule
Schedules propagation of messages from a queue to a destination identified by a specific database link
Unschedules previously scheduled propagation of messages from a queue to a destination identified by a specific database link
Verifies that the source and destination queues have identical types
This section lists and describes the DBMS_AQADM miscellaneous subprograms.
Table 24-7 Miscellaneous Subprograms
Used to get different parameters for sharded queues at queue or database level.
Retrieves the value of Oracle Database Advanced Queuing maximum streams pool memory limit
Retrieves the value of Oracle Database Advanced Queuing minimum streams pool memory limit
Retrieves the value of watermark set by the SET_WATERMARK Procedure
Used to set different parameters for sharded queues at queue or database level.
Used for Oracle Database Advanced Queuing to specify and limit maximum streams pool memory use
Used for Oracle Database Advanced Queuing to specify and limit minimum streams pool memory use
Used for Oracle Database Advanced Queuing notification to specify and limit memory use
Used to unset different parameters for sharded queues at queue or database level.
This section lists and describes the DBMS_AQADM agent subprograms.
Table 24-8 Oracle Streams AQ Agent Subprograms
Alters an agent registered for Oracle Database Advanced Queuing Internet access, and an Oracle Database Advanced Queuing agent that accesses secure queues
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
Revokes the privileges of a specific database user from an Oracle Database Advanced Queuing Internet agent
Drops an agent that was previously registered for Oracle Database Advanced Queuing Internet access
Grants an Oracle Database Advanced Queuing Internet agent the privileges of a specific database user
This section lists and describes the DBMS_AQADM alias subprograms.
Table 24-9 Alias Subprograms
Creates an alias for a queue, agent, or a JMS ConnectionFactory in LDAP
Drops an alias for a queue, agent, or JMS ConnectionFactory in LDAP
This section lists and describes the DBMS_AQADM package subprograms.
Table 24-10 DBMS_AQADM Package Subprograms
Creates an alias for a queue, agent, or a JMS ConnectionFactory in LDAP
Adds a default subscriber to a queue
Alters an agent registered for Oracle Database Advanced Queuing Internet access, and an Oracle Database Advanced Queuing agent that accesses secure queues
Alters parameters for a propagation schedule
Alters existing properties of a queue
Alters the existing properties of a queue table
Provides user the ability to alter the cache_hint and comment for the sharded queue
Alters existing properties of a subscriber to a specified queue
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
Creates a nonpersistent RAW queue
Creates a queue in the specified queue table
Creates a queue and its queue table for a sharded queue all together.
Creates an exception queue.
Creates a queue table for messages of a predefined type
Drops an alias for a queue, agent, or JMS ConnectionFactory in LDAP
Revokes the privileges of a specific database user from an Oracle Database Advanced Queuing Internet agent
Disables a propagation schedule
Drops an agent that was previously registered for Oracle Database Advanced Queuing Internet access
Drops an existing queue
Drops an existing sharded queue from the database queuing system
Drops an existing queue table
Grants an Oracle Database Advanced Queuing Internet agent the privileges of a specific database user
A precondition for the enqueue of JMS types and XML types
Enables a previously disabled propagation schedule
Retrieves the value of Oracle Database Advanced Queuing maximum streams pool memory limit
Retrieves the value of Oracle Database Advanced Queuing minimum streams pool memory limit
Used to get different parameters for sharded queues at queue or database level.
Retrieves the value of watermark set by the SET_WATERMARK Procedure
Grants privileges on a queue to users and roles
Grants Oracle Database Advanced Queuing system privileges to users and roles
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
Purges messages from queue tables
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
Removes a default subscriber from a queue
Revokes privileges on a queue from users and roles
Revokes Oracle Database Advanced Queuing system privileges from users and roles
Schedules propagation of messages from a queue to a destination identified by a specific database link
Used to set different parameters for sharded queues at queue or database level.
Used for Oracle Database Advanced Queuing to specify and limit maximum streams pool memory use
Used for Oracle Database Advanced Queuing to specify and limit minimum streams pool memory use
Used for Oracle Database Advanced Queuing notification to specify and limit memory use
Enables the specified queue for enqueuing or dequeuing
Disables enqueuing or dequeuing on the specified queue
Unschedules previously scheduled propagation of messages from a queue to a destination identified by a specific database link
Used to unset different parameters for sharded queues at queue or database level.
Verifies that the source and destination queues have identical types
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.
DBMS_AQADM.ADD_ALIAS_TO_LDAP( alias IN VARCHAR2, obj_location IN VARCHAR2);
Table 24-11 ADD_ALIAS_TO_LDAP Procedure Parameters
Name of the alias. Example: west_shipping.
The distinguished name of the object (queue, agent or connection factory) to which alias refers.
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.
This procedure adds a default subscriber to a queue.
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);
Table 24-12 ADD_SUBSCRIBER Procedure Parameters
Name of the queue.
Agent on whose behalf the subscription is being defined.
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.
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.
If TRUE , propagation is from queue-to-queue.
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 .
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 => 'PRIORITYNote that these are all single quotation marks.
24.4.3 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.
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 )Table 24-13 ALTER_AQ_AGENT Procedure Parameters
Specifies the username of the Oracle Database Advanced Queuing Internet agent.
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.
TRUE means the agent can access Oracle Database Advanced Queuing through HTTP. FALSE means the agent cannot access Oracle Database Advanced Queuing through HTTP.
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.
TRUE means the agent can access Oracle Database Advanced Queuing through any protocol (HTTP or SMTP).
24.4.4 ALTER_PROPAGATION_SCHEDULE Procedure
This procedure alters parameters for a propagation schedule.
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);Table 24-14 ALTER_PROPAGATION_SCHEDULE Procedure Parameters
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 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 of the propagation window in seconds. A NULL value means the propagation window is forever or until the propagation is unscheduled.
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 .
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.
Name of the target queue to which messages are to be propagated in the form of a dblink
24.4.5 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.
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);Table 24-15 ALTER_QUEUE Procedure Parameters
Name of the queue that is to be altered
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.
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 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.
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.
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.
24.4.6 ALTER_QUEUE_TABLE Procedure
This procedure alters the existing properties of a queue table.
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);Table 24-16 ALTER_QUEUE_TABLE Procedure Parameters
Name of a queue table to be created.
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.
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.
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.
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 .
24.4.7 ALTER_SHARDED_QUEUE Procedure
This procedure provides user the ability to alter a sharded queue.
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);Table 24-17 ALTER_SHARDED_QUEUE Procedure Parameters
This parameter specifies the name of the sharded queue. A maximum of 128 characters are allowed.
The maximum number of retries allowed.
The comment of the queue.
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 .
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 .
24.4.8 ALTER_SUBSCRIBER Procedure
This procedure alters existing properties of a subscriber to a specified queue. Only the rule can be altered.
DBMS_AQADM.ALTER_SUBSCRIBER ( queue_name IN VARCHAR2, subscriber IN sys.aq$_agent, rule IN VARCHAR2 transformation IN VARCHAR2);Table 24-18 ALTER_SUBSCRIBER Procedure Parameters
Name of the queue.
Agent on whose behalf the subscription is being altered. See "AQ__AGENT Type" .
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 .
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.
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.
24.4.9 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.
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 )Table 24-19 CREATE_AQ_AGENT Procedure Parameters
Specifies the username of the Oracle Database Advanced Queuing Internet agent.
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.
TRUE means the agent can access Oracle Database Advanced Queuing through HTTP. FALSE means the agent cannot access Oracle Database Advanced Queuing through HTTP.
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.
TRUE means the agent can access Oracle Database Advanced Queuing through any protocol (HTTP or SMTP).
The SYS.AQ$INTERNET_USERS view has a list of all Oracle Database Advanced Queuing Internet agents.
24.4.10 CREATE_NP_QUEUE Procedure
This procedure creates a nonpersistent RAW queue.
Nonpersistent queues are deprecated as of Release 10gR2. Oracle recommends using buffered messaging.
DBMS_AQADM.CREATE_NP_QUEUE ( queue_name IN VARCHAR2, multiple_consumers IN BOOLEAN DEFAULT FALSE, comment IN VARCHAR2 DEFAULT NULL);Table 24-20 CREATE_NP_QUEUE Procedure Parameters
Name of the nonpersistent queue that is to be created. The name must be unique within a schema and must follow object name guidelines in Oracle Database SQL Language Reference.
FALSE means queues created in the table can only have one consumer for each message. This is the default. TRUE means queues created in the table can have multiple consumers for each message.
Note that this parameter is distinguished at the queue level, because a nonpersistent queue does not inherit this characteristic from any user-created queue table.
User-specified description of the queue. This user comment is added to the queue catalog.
The queue may be either single-consumer or multiconsumer queue. All queue names must be unique within a schema. The queues are created in a 8.1-compatible or higher system-created queue table ( AQ$_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.
24.4.11 CREATE_QUEUE Procedure
This procedure creates a queue in the specified queue table.
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);Table 24-21 CREATE_QUEUE Procedure Parameters
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.
Name of the queue table that will contain the queue.
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.
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.
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.
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.
Reserved for future use. FALSE is the default. TRUE is not permitted in this release.
User-specified description of the queue. This user comment is added to the queue catalog.
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.
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.
24.4.12 CREATE_QUEUE_TABLE Procedure
This procedure creates a queue table for messages of a predefined type.
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);Table 24-22 CREATE_QUEUE_TABLE Procedure Parameters
Name of a queue table to be created
Type of the user data stored. See Type Name inDBMS_AQ Data Types for valid values for this parameter.
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.
The columns to be used as the sort key in ascending order. This parameter has the following format:
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.
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 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.
User-specified description of the queue table. This user comment is added to the queue catalog.
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.
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.
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.
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 .
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.
DBMS_AQADM.REPLICATION_MODE if queue is being created in the Replication Mode or else DBMS_AQADM.NONE . Default is DBMS_AQADM.NONE .
The sort keys for dequeue ordering, if any, must be defined at table creation time. The following objects are created at this time:
For 8.1-compatible or higher queue tables, the following index-organized tables are created:
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 Oracle8 i 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.
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.
Sharded queues may be either a single consumer or a multi-consumer queue.
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);
Table 24-23 CREATE_SHARDED_QUEUE Procedure Parameters
This required parameter specifies the name of the new queue. Maximum of 128 characters allowed.
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.
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.
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.
This optional parameter is a user-specified description of the queue table. This user comment is added to the queue catalog.
Payload can be RAW , DBMS_AQADM.JMS_TYPE , or an object type. Default is DBMS_AQADM.JMS_TYPE .
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 .
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 .
The CREATE_EXCEPTION_QUEUE API creates an exception queue for a sharded queue.
PROCEDURE CREATE_EXCEPTION_QUEUE( sharded_queue_name IN VARCHAR2, exception_queue_name IN VARCHAR2 DEFAULT NULL );
Table 24-24 CREATE_EXCEPTION_QUEUE Procedure Parameters
The name of the sharded queue.
The name of the exception queue.
This procedure drops an alias for a queue, agent, or JMS ConnectionFactory in LDAP.
DBMS_AQADM.DEL_ALIAS_FROM_LDAP( alias IN VARCHAR2);
Table 24-25 DEL_ALIAS_FROM_LDAP Procedure Parameters
The alias to be removed.
This procedure revokes the privileges of a specific database user from an Oracle Database Advanced Queuing Internet agent.
DBMS_AQADM.DISABLE_DB_ACCESS ( agent_name IN VARCHAR2, db_username IN VARCHAR2)
Table 24-26 DISABLE_DB_ACCESS Procedure Parameters
Specifies the username of the Oracle Database Advanced Queuing Internet agent.
Specifies the database user whose privileges are to be revoked from the Oracle Database Advanced Queuing Internet agent.
The Oracle Database Advanced Queuing Internet agent should have been previously granted those privileges using the ENABLE_DB_ACCESS Procedure.
This procedure disables a propagation schedule.
DBMS_AQADM.DISABLE_PROPAGATION_SCHEDULE ( queue_name IN VARCHAR2, destination IN VARCHAR2 DEFAULT NULL, destination_queue IN VARCHAR2 DEFAULT NULL);
Table 24-27 DISABLE_PROPAGATION_SCHEDULE Procedure Parameters
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 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.
Name of the target queue to which messages are to be propagated in the form of a dblink
This procedure drops an agent that was previously registered for Oracle Database Advanced Queuing Internet access.
DBMS_AQADM.DROP_AQ_AGENT ( agent_name IN VARCHAR2)
Table 24-28 DROP_AQ_AGENT Procedure Parameters
Specifies the username of the Oracle Database Advanced Queuing Internet agent
This procedure drops an existing queue.
DBMS_AQADM.DROP_QUEUE ( queue_name IN VARCHAR2, auto_commit IN BOOLEAN DEFAULT TRUE);
Table 24-29 DROP_QUEUE Procedure Parameters
Name of the queue that is to be dropped.
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.
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.
This procedure drops an existing queue table.
DBMS_AQADM.DROP_QUEUE_TABLE ( queue_table IN VARCHAR2, force IN BOOLEAN DEFAULT FALSE, auto_commit IN BOOLEAN DEFAULT TRUE);
Table 24-30 DROP_QUEUE_TABLE Procedure Parameters
Name of a queue table to be dropped.
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.
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.
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.
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.
DBMS_AQADM.DROP_SHARDED_QUEUE( queue_name IN VARCHAR2, force IN BOOLEAN DEFAULT FALSE )
Table 24-31 DROP_SHARDED_QUEUE Procedure Parameters
This required parameter specifies the name of the sharded queue.
The sharded queue is dropped even if the queue is not stopped.
This procedure grants an Oracle Database Advanced Queuing Internet agent the privileges of a specific database user.
DBMS_AQADM.ENABLE_DB_ACCESS ( agent_name IN VARCHAR2, db_username IN VARCHAR2)
Table 24-32 ENABLE_DB_ACCESS Procedure Parameters
Specifies the username of the Oracle Database Advanced Queuing Internet agent.
Specified the database user whose privileges are to be granted to the Oracle Database Advanced Queuing Internet agent.
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.
Enqueue JMS types and XML types.
DBMS_AQADM.ENABLE_JMS_TYPES ( queue_table IN VARCHAR2);
Table 24-33 ENABLE_JMS_TYPES Procedure Parameters
Specifies name of the queue table to be enabled for JMS and XML types.
This procedure enables a previously disabled propagation schedule.
DBMS_AQADM.ENABLE_PROPAGATION_SCHEDULE ( queue_name IN VARCHAR2, destination IN VARCHAR2 DEFAULT NULL, destination_queue IN VARCHAR2 DEFAULT NULL);
Table 24-34 ENABLE_PROPAGATION_SCHEDULE Procedure Parameters
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 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.
Name of the target queue to which messages are to be propagated in the form of a dblink
This procedure retrieves the value of Oracle Database Advanced Queuing maximum streams pool memory limit.
DBMS_AQADM.GET_MAX_STREAMS_POOL ( value OUT NUMBER);
Table 24-35 GET_MAX_STREAMS_POOL Procedure Parameter
Value in megabytes.
This procedure retrieves the value of Oracle Database Advanced Queuing minimum streams pool memory limit.
DBMS_AQADM.GET_MIN_STREAMS_POOL ( value OUT NUMBER);
Table 24-36 GET_MIN_STREAMS_POOL Procedure Parameter
Value in megabytes.
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.
PROCEDURE GET_QUEUE_PARAMETER( queue_name IN VARCHAR2, param_name IN VARCHAR2, param_value OUT NUMBER);
Table 24-37 GET_QUEUE_PARAMETER Procedure Parameters
The name of the sharded queue.
The name of the parameter. Table 24-38 and Table 24-39 describe the valid parameter names.
The value of the parameter.
Table 24-38 Sharded queue parameters
Maximum number of shards allowed for the queue.
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.
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 24-39 Key-based Parameters
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.
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 24-1 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$GET_KEY_SHARD=RED', pval); dbms_output.put_line('The key RED is mapped to shard id ' || pval); END; /
Example 24-2 Key to instance mapping
User sharding performs best when cross instance enqueues are not involved. To know the instance where a key can be enqueued without any cross instance enqueue, submit the following:
declare pval number; begin dbms_aqadm.get_queue_parameter('MY_SHQ1', 'AQ$GET_KEY_SHARD_INST=RED', pval); dbms_output.put_line('The key RED is owned by instance id ' || pval); END; /
This procedure retrieves the value of watermark set by SET_WATERMARK .
DBMS_AQADM.GET_WATERMARK ( wmvalue IN NUMBER);
Table 24-40 GET_WATERMARK Procedure Parameter
Watermark value in megabytes.
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.
DBMS_AQADM.GRANT_QUEUE_PRIVILEGE ( privilege IN VARCHAR2, queue_name IN VARCHAR2, grantee IN VARCHAR2, grant_option IN BOOLEAN := FALSE);
Table 24-41 GRANT_QUEUE_PRIVILEGE Procedure Parameters
The Oracle Database Advanced Queuing queue privilege to grant. The options are ENQUEUE , DEQUEUE , and ALL . ALL means both ENQUEUE and DEQUEUE .
Name of the queue.
Grantee(s). The grantee(s) can be a user, a role, or the PUBLIC role.
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 .
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.
Starting from Oracle Database 12 c Release 2, MANAGE_ANY , ENQUEUE_ANY , and DEQUEUE_ANY privileges will not allow access to SYS owned queues by users other than SYS .
DBMS_AQADM.GRANT_SYSTEM_PRIVILEGE ( privilege IN VARCHAR2, grantee IN VARCHAR2, admin_option IN BOOLEAN := FALSE);
Table 24-42 GRANT_SYSTEM_PRIVILEGE Procedure Parameters
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.
Starting from Oracle Database 12 c Release 2, MANAGE_ANY , ENQUEUE_ANY , and DEQUEUE_ANY privileges will not allow access to SYS owned queues by users other than SYS .
Grantee(s). The grantee(s) can be a user, a role, or the PUBLIC role.
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 .
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.
DBMS_AQADM.MIGRATE_QUEUE_TABLE ( queue_table IN VARCHAR2, compatible IN VARCHAR2);
Table 24-43 MIGRATE_QUEUE_TABLE Procedure Parameters
Specifies name of the queue table to be migrated.
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.
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.
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.
Table 24-44 PURGE_QUEUE_TABLE Procedure Parameters
Specifies the name of the queue table to be purged.
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).
Type aq$_purge_options_t contains a block parameter and a delivery_mode parameter.
This function returns the subscribers to an 8.0-compatible multiconsumer queue in the PL/SQL index by table collection type DBMS_AQADM.AQ$_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.
DBMS_AQADM.QUEUE_SUBSCRIBERS ( queue_name IN VARCHAR2); RETURN aq$_subscriber_list_t IS
Table 24-45 QUEUE_SUBSCRIBERS Function Parameters
Specifies the queue whose subscribers are to be printed.
This procedure removes a default subscriber from a queue. This operation takes effect immediately, and the containing transaction is committed. All references to the subscriber in existing messages are removed as part of the operation.
DBMS_AQADM.REMOVE_SUBSCRIBER ( queue_name IN VARCHAR2, subscriber IN sys.aq$_agent);
Table 24-46 REMOVE_SUBSCRIBER Procedure Parameters
Name of the queue.
Agent who is being removed. See AQ$_AGENT Type.
This procedure revokes privileges on a queue from users and roles. The privileges are ENQUEUE or DEQUEUE .
DBMS_AQADM.REVOKE_QUEUE_PRIVILEGE ( privilege IN VARCHAR2, queue_name IN VARCHAR2, grantee IN VARCHAR2);
Table 24-47 REVOKE_QUEUE_PRIVILEGE Procedure Parameters
The Oracle Database Advanced Queuing queue privilege to revoke. The options are ENQUEUE , DEQUEUE , and ALL . ALL means both ENQUEUE and DEQUEUE .
Name of the queue.
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.
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.
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 12 c Release 2, MANAGE_ANY , ENQUEUE_ANY , and DEQUEUE_ANY privileges will not allow access to SYS owned queues by users other than SYS .
DBMS_AQADM.REVOKE_SYSTEM_PRIVILEGE ( privilege IN VARCHAR2, grantee IN VARCHAR2);
Table 24-48 REVOKE_SYSTEM_PRIVILEGE Procedure Parameters
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.
Starting from Oracle Database 12 c Release 2, MANAGE_ANY , ENQUEUE_ANY , and DEQUEUE_ANY privileges will not allow access to SYS owned queues by users other than SYS .
Grantee(s). The grantee(s) can be a user, a role, or the PUBLIC role.
This procedure schedules propagation of messages from a queue to a destination identified by a specific database link.
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);
Table 24-49 SCHEDULE_PROPAGATION Procedure Parameters
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 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.
Initial start time for the propagation window for messages from the source queue to the destination.
Duration of the propagation window in seconds. A NULL value means the propagation window is forever or until the propagation is unscheduled.
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.
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.
Name of the target queue to which messages are to be propagated in the form of a dblink
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
Related Topics
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.
PROCEDURE SET_QUEUE_PARAMETER( queue_name IN VARCHAR2, param_name IN VARCHAR2, param_value IN NUMBER);
Table 24-50 SET_QUEUE_PARAMETER Procedure Parameters
The name of the sharded queue.
The name of the parameter. Table 24-51 and Table 24-52 describe the valid parameter names.
The value of the parameter.
Table 24-51 Sharded queue parameters
Maximum number of shards allowed for the queue.
Default value is 20,000.
This is the size of each partition for allocation of memory in a shard. Each shard consists of multiple subshards, which are allocated, used, and purged automatically based on message enqueue and dequeue rate for the shard.
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.
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 24-52 Key-based Parameters
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.
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 24-3 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 24-4 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 24-5 Setting or changing the number of shards
Once a queue is created, it can have a maximum of 5 shards by default in non-Oracle RAC databases. In Oracle RAC databases, each queue can have a maximum of 5 shards per database instance by default.
execute dbms_aqadm.set_queue_parameter('MY_SHQ1', 'SHARD_NUM', 200);Odd numbered shard identifiers are reserved for internal use. In the above example, the 200 shard identifiers used will be 0, 2, 4, …, 398.
Example 24-6 Enabling the scrambling and flow control feature using the queue level param/knob enhancement
Spread the concurrent dequeuers across different blocks/buffers to reduce "buffer busy waits" contention, enable scrambled dequeues by setting the following queue parameter.
dbms_aqadm.set_queue_parameter('.', 'CQ_SCRAMBLED_DEQ', 1);Internally restrict the number of concurrent sessions which execute the dequeue select for update on a queue, eventually causing row lock contention and buffer busy waits contention, enable Dequeue Flow Control by setting the following queue parameter:
dbms_aqadm.set_queue_parameter('.', 'CQ_DEQ_FLOWCONTROL', N);where N is number of internal dequeue sessions allowed to do core work of contentions.
M is the number of actual external dequeue sessions.
This procedure is used for Oracle Database Advanced Queuing to specify and limit maximum streams pool memory use.
DBMS_AQADM.SET_MAX_STREAMS_POOL ( value IN NUMBER);
Table 24-53 SET_MAX_STREAMS_POOL Procedure Parameter
Value in megabytes.
This procedure is used for Oracle Database AQ to specify and limit minimum streams pool memory use.
DBMS_AQADM.SET_MIN_STREAMS_POOL ( value IN NUMBER);
Table 24-54 SET_MIN_STREAMS_POOL Procedure Parameter
Value in megabytes.
This procedure is used for Oracle Database Advanced Queuing notification to specify and limit memory use.
DBMS_AQADM.SET_WATERMARK ( wmvalue IN NUMBER);
Table 24-55 SET_WATERMARK Procedure Parameter
Watermark value in megabytes.
This procedure enables the specified queue for enqueuing or dequeuing.
DBMS_AQADM.START_QUEUE ( queue_name IN VARCHAR2, enqueue IN BOOLEAN DEFAULT TRUE, dequeue IN BOOLEAN DEFAULT TRUE);
Table 24-56 START_QUEUE Procedure Parameters
Name of the queue to be enabled
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.
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.
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.
This procedure disables enqueuing or dequeuing on the specified queue.
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);
Table 24-57 STOP_QUEUE Procedure Parameters
Name of the queue to be disabled
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.
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.
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.
Specifies whether the queue should be stopped.
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.
This procedure unschedules previously scheduled propagation of messages from a queue to a destination identified by a specific database link.
DBMS_AQADM.UNSCHEDULE_PROPAGATION ( queue_name IN VARCHAR2, destination IN VARCHAR2 DEFAULT NULL destination_queue IN VARCHAR2 DEFAULT NULL);
Table 24-58 UNSCHEDULE_PROPAGATION Procedure Parameters
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 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.
Name of the target queue to which messages are to be propagated in the form of a dblink
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.
PROCEDURE UNSET_QUEUE_PARAMETER( queue_name IN VARCHAR2, param_name IN VARCHAR2);
Table 24-59 UNSET_QUEUE_PARAMETER Procedure Parameters
The name of the sharded queue.
The name of the parameter. Table 24-60 and Table 24-61 describe the valid parameter names.
Table 24-60 Sharded queue parameters
Maximum number of shards allowed for the queue.
Default value is 20,000.
This is the size of each partition for allocation of memory in a shard. Each shard consists of multiple subshards, which are allocated, used, and purged automatically based on message enqueue and dequeue rate for the shard.
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.
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 24-61 Key-based Parameters
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.
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 24-7 Disabling the scrambling and flow control feature using the queue level param/knob enhancement
Spread the concurrent dequeuers across different blocks/buffers to reduce "buffer busy waits" contention,disable scrambled dequeues by unsetting the following queue parameter.
dbms_aqadm.unset_queue_parameter('.', 'CQ_SCRAMBLED_DEQ');Internally restrict the number of concurrent sessions which execute the dequeue select for update on a queue, eventually causing row lock contention and buffer busy waits contention, disable Dequeue Flow Control by unsetting the following queue parameter:
dbms_aqadm.unset_queue_parameter('MY_QUEUE', 'CQ_DEQ_FLOWCONTROL');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.
DBMS_AQADM.VERIFY_QUEUE_TYPES ( src_queue_name IN VARCHAR2, dest_queue_name IN VARCHAR2, destination IN VARCHAR2 DEFAULT NULL, rc OUT BINARY_INTEGER);
Table 24-62 VERIFY_QUEUE_TYPES Procedure Parameters
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.
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 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.
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 .