pg_trace
(PHP 4 >= 4.0.1, PHP 5, PHP 7, PHP 8)
pg_trace — Enable tracing a PostgreSQL connection
Description
string
$filename,string
$mode = "w",?PgSql\Connection
$connection = null,int
$trace_mode = 0): bool
pg_trace() enables tracing of the PostgreSQL frontend/backend communication to a file. To fully understand the results, one needs to be familiar with the internals of PostgreSQL communication protocol.
For those who are not, it can still be useful for tracing errors in queries sent to the server, you could do for example grep '^To backend' trace.log and see what queries actually were sent to the PostgreSQL server. For more information, refer to the » PostgreSQL Documentation.
Parameters
-
filename -
The full path and file name of the file in which to write the trace log. Same as in fopen().
-
mode -
An optional file access mode, same as for fopen().
-
connection -
An PgSql\Connection instance. When
connectionisnull, the default connection is used. The default connection is the last connection made by pg_connect() or pg_pconnect().WarningAs of PHP 8.1.0, using the default connection is deprecated.
-
trace_mode -
An optional trace mode with the following constants
PGSQL_TRACE_SUPPRESS_TIMESTAMPSandPGSQL_TRACE_REGRESS_MODE
Return Values
Returns true on success or false on failure.
Changelog
| Version | Description |
|---|---|
| 8.3.0 |
trace_mode has been added.
|
| 8.1.0 |
The connection parameter expects an PgSql\Connection
instance now; previously, a resource was expected.
|
| 8.0.0 |
connection is now nullable.
|
Examples
Example #1 pg_trace() example
<?php
$pgsql_conn = pg_connect("dbname=mark host=localhost");
if ($pgsql_conn) {
pg_trace('/tmp/trace.log', 'w', $pgsql_conn);
pg_query("SELECT 1");
pg_untrace($pgsql_conn);
// Now /tmp/trace.log will contain backend communication
} else {
print pg_last_error($pgsql_conn);
exit;
}
?>
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