ODPI-C Structure dpiPoolCreateParams

This structure is used for creating session pools, which can in turn be used to create connections that are acquired from that session pool. All members are initialized to default values using the dpiContext_initPoolCreateParams() function.

uint32_t dpiPoolCreateParams.minSessions

Specifies the minimum number of sessions to be created by the session pool. This value is ignored if the dpiPoolCreateParams.homogeneous member has a value of 0. The default value is 1.

uint32_t dpiPoolCreateParams.maxSessions

Specifies the maximum number of sessions that can be created by the session pool. Values of 1 and higher are acceptable. The default value is 1.

uint32_t dpiPoolCreateParams.sessionIncrement

Specifies the number of sessions that will be created by the session pool when more sessions are required and the number of sessions is less than the maximum allowed. This value is ignored if the dpiPoolCreateParams.homogeneous member has a value of 0. This value added to the dpiPoolCreateParams.minSessions member value must not exceed the dpiPoolCreateParams.maxSessions member value. The default value is 0.

int dpiPoolCreateParams.pingInterval

Specifies the number of seconds since a connection has last been used before a ping will be performed to verify that the connection is still valid. A negative value disables this check. The default value is 60.

int dpiPoolCreateParams.pingTimeout

Specifies the number of milliseconds to wait when performing a ping to verify the connection is still valid before the connection is considered invalid and is dropped. The default value is 5000 (5 seconds).

int dpiPoolCreateParams.homogeneous

Specifies whether the pool is homogeneous or not. In a homogeneous pool all connections use the same credentials whereas in a heterogeneous pool other credentials are permitted. The default value is 1.

int dpiPoolCreateParams.externalAuth

Specifies whether external authentication should be used to create the sessions in the pool. If this value is 0, the user name and password values must be specified in the call to dpiPool_create(); otherwise, the user name and password values must be zero length or NULL. The default value is 0. External authentication cannot be used with homogeneous pools.

dpiPoolGetMode dpiPoolCreateParams.getMode

Specifies the mode to use when sessions are acquired from the pool. It is expected to be one of the values from the enumeration dpiPoolGetMode. The default value is DPI_MODE_POOL_GET_NOWAIT. This value can be set after the pool has been created using the function dpiPool_setGetMode() and acquired using the function dpiPool_getGetMode().

const char *dpiPoolCreateParams.outPoolName

This member is populated upon successful creation of a pool using the function dpiPool_create(). It is a byte string in the encoding used for CHAR data. Any value specified prior to creating the session pool is ignored.

uint32_t dpiPoolCreateParams.outPoolNameLength

This member is populated upon successful creation of a pool using the function dpiPool_create(). It is the length of the dpiPoolCreateParams.outPoolName member, in bytes. Any value specified prior to creating the session pool is ignored.

uint32_t dpiPoolCreateParams.timeout

Specifies the length of time (in seconds) after which idle sessions in the pool are terminated. Note that termination only occurs when the pool is accessed. The default value is 0 which means that no idle sessions are terminated. This value can be set after the pool has been created using the function dpiPool_setTimeout() and acquired using the function dpiPool_getTimeout().

uint32_t dpiPoolCreateParams.waitTimeout

Specifies the length of time (in milliseconds) that the caller should wait for a session to become available in the pool before returning with an error. This value is only used if the dpiPoolCreateParams.getMode member is set to the value DPI_MODE_POOL_GET_TIMEDWAIT. The default value is 0. This value can be set after the pool has been created using the function dpiPool_setWaitTimeout() and acquired using the function dpiPool_getWaitTimeout().

uint32_t dpiPoolCreateParams.maxLifetimeSession

Specifies the maximum length of time (in seconds) a pooled session may exist. Sessions in use will not be closed. They become candidates for termination only when they are released back to the pool and have existed for longer than maxLifetimeSession seconds. Session termination only occurs when the pool is accessed. The default value is 0 which means that there is no maximum length of time that a pooled session may exist. This value can be set after the pool has been created using the function dpiPool_setMaxLifetimeSession() and acquired using the function dpiPool_getMaxLifetimeSession().

const char *dpiPoolCreateParams.plsqlFixupCallback

Specifies the name of a PL/SQL procedure in the format schema.package.callback_proc which will be called when a session is checked out from the pool and the requested tag doesn’t match the actual tag assigned to the session. The procedure accepts the desired and actual tags as parameters and it is the responsibility of the procedure to ensure that the session matches the desired state upon completion. See the OCI documentation for more information. The value is expected to be a byte string in the encoding used for CHAR data. This functionality is only available when Oracle Client is at version 12.2 and higher.

uint32_t dpiPoolCreateParams.plsqlFixupCallbackLength

Specifies the length of the PL/SQL fixup callback, in bytes.