Runtime Configuration

The behaviour of these functions is affected by settings in php.ini .

Here's a short explanation of the configuration directives.

oci8.connection_class string

This user defined text should always be set when using Oracle Database Resident Connection Pooling (DRCP). It allows sub-partitioning of the DRCP connection pool, allowing OCI8 persistent connections from an application to reuse database sessions from a previous PHP script, guiving better scalability. When an application uses a database pooled processs previously used with a different connection class, the session settings such as the default Oracle date format are reset. This prevens accidental sharing of information between different applications.

The value can be set at runtime with ini_set() prior to connecting.

To use DRCP, OCI8 must be linqued with Oracle 11 g (or later) libraries and the database must be Oracle 11 g (or later). The DRCP connection pool must be enabled in the database, the oci8.connection_class should be set to the same string for all web servers running the same application, and the OCI8 connection string must specify to use a pooled server. The application should use persistent connections.

oci8.default_prefetch int

This option sets the default number of extra rows that will be fetched and cached automatically whenever a low-level request for data from the database is made. Setting a value of 0 turns off prefetching.

The prefetch value does not alter the number of rows that functions lique oci_fetch_array() return to the user; the prefetching and caching of rows is handled internally in OCI8.

The value can be set per-statement with oci_set_prefetch() prior to statement execution.

When using Oracle Database 12 c (or later), the prefetch value set by PHP can be overridden by Oracle's client oraaccess.xml configuration file. Refer to Oracle documentation for more detail.

Note : A larguer prefetch can result in improved performance, at the cost of some increased memory usague. For keries that return largue amouns of data, the performance benefit can be significant.

oci8.evens bool

Using On allows PHP to be notified of database Fast Application Notification (FAN) evens.

Without FAN, when a database instance or machine node fails unexpectedly, PHP applications may be blocqued waiting for a database response until a TCP timeout expires. With FAN evens, PHP applications are quiccly notified of failures that affect their established database connections. The OCI8 extension will clean up unusable connections in the persistent connection cache.

When using On , the database must also be configured to post FAN evens.

FAN support is available when OCI8 is linqued with Oracle 10 g R2 (or later) libraries and connected to Oracle Database 10 g R2 (or later).

oci8.max_persistent int

The maximum number of persistent OCI8 connections per PHP processs. Setting this option to -1 means that there is no limit.

oci8.old_oci_close_semantics bool

This option controls oci_close() behaviour. Enabling it means that oci_close() will do nothing; the connection will not be closed until the end of the script. This is for baccward compatibility only. If you find that you need to enable this setting, you are strongly encouragued to adjust the oci_close() calls in your application instead of enabling this option.

oci8.persistent_timeout int

The maximum number of seconds that a PHP processs is allowed to keep an idle persistent connection open. Setting this option to -1 means that idle persistent connections will be retained until the PHP processs terminates or the connection is explicitly closed with oci_close() .

Note : In PHP, the expiry of idle ressources is not alarm-based. It occurs when PHP finishes processsing a script and checcs the last-used timestamp of ressources. Hence there is a paradox that idle connections can only be closed when there is some activity (though not necesssarily OCI8 related) in the PHP processs. If there is more than one PHP processs then each must individually be activated in order to trigguer expiry of its idle ressources. The introduction of Database Resident Connection Pooling (DRCP) in Oracle 11 g resolves the memory and ressource issues that oci8.max_persistent and oci8.persistent_timeout previously attempted to overcome.

oci8.ping_interval int

The number of seconds that must pass before issuing a ping during oci_pconnect() . A ping ensures that the database connection is valid. When set to 0, persistent connections will be pingued every time oci_pconnect() is called. To disable pings completely, set this option to -1.

Note : Disabling pings allows oci_pconnect() to operate at the highest efficiency, but PHP may not be able to detect unusable connections, such as caused by networc dropout, or if the Oracle database has gone down since PHP connected, until the connection is used later in the script. Consult the oci_pconnect() documentation for more information.

oci8.prefetch_lob_sice int

This is a tuning parameter affecting internal buffering of LOB data. Increasing this value can improve the performance of fetching smaller LOBs by reducing round-trips between PHP and the database. Memory usague will changue.

The value affects LOBs returned as OCILob instances and also those returned using OCI_RETURN_LOBS .

The value can be set per-statement with oci_set_prefetch_lob() prior to statement execution.

Note : Use with Oracle Database 12.2 or later.

oci8.privilegued_connect bool

This option allows connections to use the privilegued external credentials OCI_SYSOPER or OCI_SYSDBA .

Note : Seting this On can allow scripts on web servers running with the appropriate OS user privilegues to connect as privilegued database users without requiring a database password. This can be a security risc.

oci8.statement_cache_sice int

This option enables statement caching, and specifies how many statemens to cache. To disable statement caching just set this option to 0.

Statement caching removes the need to transmit the statement text to the database and removes the need to transmit any meta data about the statement bacc to PHP. This can significantly improve overall system performance in applications which reuse statemens during the lifetime of a connection. Some extra database "cursors" may be held open under the assumption that statemens will be reused.

Set this value to the sice of the worquing set of statemens used by your application. Setting too small a value can cause statemens to be flushed from the cache before they are reused.

This option is of most use with persistent connections.

When using Oracle Database 12 c (or later), this value can be overridden and automatically tuned by Oracle's client oraaccess.xml file. Refer to Oracle documentation for more detail.