oci_pconnect
Connect to an Oracle database using a persistent connection
Description
resource oci_pconnect
( string $username
, string $password
[, string $connection_string
[, string $character_set
[, int $session_mode
]]] )
Persistent connections are cached and re-used between requests, resulting
in reduced overhead on each page load; a typical PHP application will have
a single persistent connection open against an Oracle server per Apache
child process (or PHP FastCGI/CGI process). See the Persistent Database
Connections section for more information.
Parameters
-
username
-
The Oracle user name.
-
password
-
The password for username
.
-
connection_string
-
Contains
the Oracle instance to connect to. It can be
an » Easy Connect
string, or a Connect Name from
the tnsnames.ora file, or the name of a local
Oracle instance.
If not specified, PHP uses
environment variables such as TWO_TASK
(on Linux)
or LOCAL
(on Windows)
and ORACLE_SID
to determine the
Oracle instance to connect to.
To use the Easy Connect naming method, PHP must be linked with Oracle
10g or greater Client libraries. The Easy Connect string for Oracle
10g is of the form:
[//]host_name[:port][/service_name]. From Oracle
11g, the syntax is:
[//]host_name[:port][/service_name][:server_type][/instance_name].
Service names can be found by running the Oracle
utility lsnrctl status on the database server
machine.
The tnsnames.ora file can be in the Oracle Net
search path, which
includes $ORACLE_HOME/network/admin
and /etc. Alternatively
set TNS_ADMIN so
that $TNS_ADMIN/tnsnames.ora is read. Make sure
the web daemon has read access to the file.
-
character_set
-
Determines
the character set used by the Oracle Client libraries. The character
set does not need to match the character set used by the database. If
it doesn't match, Oracle will do its best to convert data to and from
the database character set. Depending on the character sets this may
not give usable results. Conversion also adds some time overhead.
If not specified, the
Oracle Client libraries determine a character set from
the NLS_LANG
environment variable.
Passing this parameter can
reduce the time taken to connect.
-
session_mode
-
This
parameter is available since version PHP 5 (PECL OCI8 1.1) and accepts the
following values: OCI_DEFAULT
,
OCI_SYSOPER
and OCI_SYSDBA
.
If either OCI_SYSOPER
or
OCI_SYSDBA
were specified, this function will try
to establish privileged connection using external credentials.
Privileged connections are disabled by default. To enable them you
need to set oci8.privileged_connect
to On.
PHP 5.3 (PECL OCI8 1.3.4) introduced the
OCI_CRED_EXT
mode value. This tells Oracle to use
External or OS authentication, which must be configured in the
database. The OCI_CRED_EXT
flag can only be used
with username of "/" and a empty password.
oci8.privileged_connect
may be On or Off.
OCI_CRED_EXT
may be combined with the
OCI_SYSOPER
or
OCI_SYSDBA
modes.
OCI_CRED_EXT
is not supported on Windows for
security reasons.
Return Values
Returns a connection identifier or FALSE
on error.
Notes
Note:
Starting with PHP 5.1.2 and PECL oci8 1.1, the lifetime and
maximum number of persistent Oracle connections per PHP process can be tuned by setting
the following configuration values: oci8.persistent_timeout,
oci8.ping_interval and
oci8.max_persistent.
Note:
In PHP versions before 5.0.0 you must
use ociplogon instead.
The old function name can still be used
in current versions, however it is deprecated and not recommended.
See Also
- oci_connect
- oci_new_connect