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oci_register_taf_callback - Register a user-defined callback function for Oracle Database TAF

oci_register_taf_callback( resource$connection, callable|null$callback ): bool

Registers a user-defined callback function to connection. If connection fails due to instance or network failure, the registered callback function will be invoked for several times during failover. See OCI8 Transparent Application Failover (TAF) Support for information.

When oci_register_taf_callback is called multiple times, each registration overwrites the previous one.

Use oci_unregister_taf_callback to explicitly unregister a user-defined callback.

TAF callback registration will NOT be saved across persistent connections, therefore the callback needs to be re-registered for a new persistent connection.



An Oracle connection identifier.


A user-defined callback to register for Oracle TAF. It can be a string of the function name or a Closure (anonymous function).

The interface of a TAF user-defined callback function is as follows:

userCallbackFn( resource$connection, int$event, int$type ): int

See the parameter description and an example on OCI8 Transparent Application Failover (TAF) Support page.

Return Values

Returns true on success or false on failure.

Related Functions

Function oci_register_taf_callback:

  • Manual

Oracle OCI8 Functions

Most used PHP functions