(PHP 4 >= 4.0.1, PHP 5, PHP 7, PHP 8)
pg_trace — Enable tracing a PostgreSQL connection
$filename,$mode = "w",$connection = null,$trace_mode = 0pg_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.
filenameThe full path and file name of the file in which to write the trace log. Same as in fopen().
modeAn optional file access mode, same as for fopen().
connectionAn PgSql\Connection instance.
When connection is null, the default connection is used.
The default connection is the last connection made by pg_connect()
or pg_pconnect().
As of PHP 8.1.0, using the default connection is deprecated.
trace_mode
An optional trace mode with the following constants
PGSQL_TRACE_SUPPRESS_TIMESTAMPS and
PGSQL_TRACE_REGRESS_MODE
| 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.
|
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;
}
?>