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Oracle® Database PL/SQL Packages and Types Reference
11g Release 2 (11.2)

Part Number E10577-03
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35 DBMS_CONNECTION_POOL

The DBMS_CONNECTION_POOL package provides an interface to manage Database Resident Connection Pool.

See Also:

Oracle Database Concepts for more information on "Database Resident Connection Pooling"

This chapter contains the following topic:


Summary of DBMS_CONNECTION_POOL Subprograms

Table 35-1 DBMS_CONNECTION_POOL Package Subprograms

Subprogram Description

ALTER_PARAM Procedure

Alters a specific configuration parameter as a standalone unit and does not affect other parameters

CONFIGURE_POOL Procedure

Configures the pool with advanced options

START_POOL Procedure

Starts the pool for operations. It is only after this call that the pool could be used by connection clients for creating sessions

STOP_POOL Procedure

Stops the pool and makes it unavailable for the registered connection clients

RESTORE_DEFAULTS Procedure

Restores the pool to default settings



ALTER_PARAM Procedure

This procedure alters a specific configuration parameter as a standalone unit and does not affect other parameters.

Syntax

DBMS_CONNECTION_POOL.ALTER_PARAM (
   pool_name     IN  VARCHAR2 DEFAULT 'SYS_DEFAULT_CONNECTION_POOL',   param_name    IN  VARCHAR2,   param_value   IN  VARCHAR2);

Parameters

Table 35-2 ALTER_PARAM Procedure Parameters

Parameter Description

pool_name

Pool to be configured. Currently only the default pool name is supported.

param_name

Any parameter name from CONFIGURE_POOL

param_value

Parameter value for param_name.


Exceptions

Table 35-3 ALTER_PARAM Procedure Exceptions

Exception Description

ORA-56500

Connection pool not found

ORA-56504

Invalid connection pool configuration parameter name

ORA-56505

Invalid connection pool configuration parameter value

ORA-56507

Connection pool alter configuration failed


Examples

DBMS_CONNECTION_POOL.ALTER_PARAM(
   'SYS_DEFAULT_CONNECTION_POOL', 'MAX_LIFETIME_SESSION', '120'); 

CONFIGURE_POOL Procedure

This procedure configures the pool with advanced options.

Syntax

DBMS_CONNECTION_POOL.CONFIGURE_POOL (
   pool_name                IN VARCHAR2 DEFAULT 'SYS_DEFAULT_CONNECTION_POOL',
   minsize                  IN NUMBER   DEFAULT 4,
   maxsize                  IN NUMBER   DEFAULT 40,
   incrsize                 IN NUMBER   DEFAULT 2,
   session_cached_cursors   IN NUMBER   DEFAULT 20,
   inactivity_timeout       IN NUMBER   DEFAULT 300,
   max_think_time           IN NUMBER   DEFAULT 120,
   max_use_session          IN NUMBER   DEFAULT 500000,
   max_lifetime_session     IN NUMBER   DEFAULT 86400);

Parameters

Table 35-4 CONFIGURE_POOL Procedure Parameters

Parameter Description

pool_name

Pool to be configured. Currently only the default pool name is supported.

minsize

Minimum number of pooled servers in the pool

maxsize

Maximum allowed pooled servers in the pool

incrsize

Pool would increment by this number of pooled server when pooled server are unavailable at application request time

session_cached_cursors

Turn on SESSION_CACHED_CURSORS for all connections in the pool. This is an existing init.ora parameter

inactivity_timeout

TTL (Time to live) for an idle session in the pool. This parameter helps to shrink the pool when it is not used to its maximum capacity. If a connection remains in the pool idle for this time, it is killed.

max_think_time

Maximum time of inactivity by the client after getting a session from the pool. If the client does not issue a database call after grabbing a server from the pool, the client will be forced to relinquish control of the pooled server and will get an ORA-xxxxx error. The freed up server may or may not be returned to the pool.

max_use_session

Maximum number of times a connection can be taken and released to the pool

max_lifetime_session

TTL (Time to live) for a pooled session


Exceptions

Table 35-5 CONFIGURE_POOL Procedure Exceptions

Exception Description

ORA-56500

Connection pool not found

ORA-56507

Connection pool alter configuration failed


Usage Notes


START_POOL Procedure

This procedure starts the pool for operations. It is only after this call that the pool could be used by connection classes for creating sessions.

Syntax

DBMS_CONNECTION_POOL.START_POOL (
   pool_name  IN  VARCHAR2 DEFAULT 'SYS_DEFAULT_CONNECTION_POOL');

Parameters

Table 35-6 START_POOL Procedure Parameters

Parameter Description

pool_name

Pool to be started. Currently only the default pool name is supported.


Exceptions

Table 35-7 START_POOL Procedure Exceptions

Exception Description

ORA-56500

Connection pool not found

ORA-56501

Connection pool startup failed


Usage Notes

If the instance is restarted (shutdown followed by startup), the pool is automatically started.


STOP_POOL Procedure

This procedure stops the pool and makes it unavailable for the registered connection classes.

Syntax

DBMS_CONNECTION_POOL.STOP_POOL (
   pool_name   IN   VARCHAR2 DEFAULT 'SYS_DEFAULT_CONNECTION_POOL');

Parameters

Table 35-8 STOP_POOL Procedure Parameters

Parameter Description

pool_name

Pool to be stopped. Currently only the default pool name is supported.


Exceptions

Table 35-9 STOP_POOL Procedure Exceptions

Exception Description

ORA-56500

Connection pool not found

ORA-56506

Connection pool shutdown failed


Usage Notes

This stops the pool and takes it offline. This does not destroy the persistent data (such as, the pool name and configuration parameters) associated with the pool.


RESTORE_DEFAULTS Procedure

This procedure restores the pool to default settings.

Syntax

DBMS_CONNECTION_POOL.RESTORE_DEFAULTS (
   pool_name   IN  VARCHAR2 DEFAULT 'SYS_DEFAULT_CONNECTION_POOL');

Parameters

Table 35-10 RESTORE_DEFAULTS Procedure Parameters

Parameter Description

pool_name

Pool to be restored. Currently only the default pool name is supported.


Exceptions

Table 35-11 RESTORE_DEFAULTS Procedure Exceptions

Exception Description

ORA-56500

Connection pool not found

ORA-56507

Connection pool alter configuration failed


Usage Notes

If the instance is restarted (shutdown followed by startup), the pool is automatically started.