From: mark dot kirkwood at catalyst dot net dot nz
Operating system: Linux 2.6.28 (Ubuntu) amd64
PHP version: 5.3CVS-2009-07-01 (snap)
PHP Bug Type: PDO related
Bug description: PDO_pgsql::query always uses implicit prepared statements if
v3 proto available
Description:
------------
If the libpq v3 protocol is available, the PDO_pgsql::query will use
implicit prepared statements. This can be a big performance hit for apps
that execute a lot of small sql statements. It would be good to be able to
switch this feature off as required.
Example code snippet to illustrate the use case is below:
Looking at the php code, it seems that either of
PDO::ATTR_EMULATE_PREPARES
PGSQL_ATTR_DISABLE_NATIVE_PREPARED_STATEMENT
should be able to do this. However neither actually have any effect in
this case.
I have a patch that makes the latter work in this case.
Reproduce code:
---------------
//Example code snippet
// (now while this cries out to be converted to use $dbh->prepare and
// $stmt->execute(), more complex cases may not just reexecute
// the same or similar sql)
//
$dbh = new PDO($url, $user);
$dbh->beginTransaction();
for ($i = 0; $i < $num_execs; $i++) {
$stmt = $dbh->query($sql);
}
//Adding these directives has no effect:
//
$dbh = new PDO($url, $user, "", array(PDO::ATTR_EMULATE_PREPARES =>
true));
//
//or
//
$dbh->setAttribute(PDO::PGSQL_ATTR_DISABLE_NATIVE_PREPARED_STATEMENT,
true);
Expected result:
----------------
Setting PGSQL_ATTR_DISABLE_NATIVE_PREPARED_STATEMENT or maybe
ATTR_EMULATE_PREPARES should stop server side prepare in PDO::query
Actual result:
--------------
Server side prepare is always used if libpq v3 protocol is detected.
--
Edit bug report at http://bugs.php.net/?id=48764&edit=1
--
Try a CVS snapshot (PHP 5.2):
http://bugs.php.net/fix.php?id=48764&r=trysnapshot52
Try a CVS snapshot (PHP 5.3):
http://bugs.php.net/fix.php?id=48764&r=trysnapshot53
Try a CVS snapshot (PHP 6.0):
http://bugs.php.net/fix.php?id=48764&r=trysnapshot60
Fixed in CVS:
http://bugs.php.net/fix.php?id=48764&r=fixedcvs
Fixed in CVS and need be documented:
http://bugs.php.net/fix.php?id=48764&r=needdocs
Fixed in release:
http://bugs.php.net/fix.php?id=48764&r=alreadyfixed
Need backtrace:
http://bugs.php.net/fix.php?id=48764&r=needtrace
Need Reproduce Script:
http://bugs.php.net/fix.php?id=48764&r=needscript
Try newer version:
http://bugs.php.net/fix.php?id=48764&r=oldversion
Not developer issue:
http://bugs.php.net/fix.php?id=48764&r=support
Expected behavior:
http://bugs.php.net/fix.php?id=48764&r=notwrong
Not enough info:
http://bugs.php.net/fix.php?id=48764&r=notenoughinfo
Submitted twice:
http://bugs.php.net/fix.php?id=48764&r=submittedtwice
register_globals:
http://bugs.php.net/fix.php?id=48764&r=globals
PHP 4 support discontinued: http://bugs.php.net/fix.php?id=48764&r=php4
Daylight Savings: http://bugs.php.net/fix.php?id=48764&r=dst
IIS Stability:
http://bugs.php.net/fix.php?id=48764&r=isapi
Install GNU Sed:
http://bugs.php.net/fix.php?id=48764&r=gnused
Floating point limitations:
http://bugs.php.net/fix.php?id=48764&r=float
No Zend Extensions:
http://bugs.php.net/fix.php?id=48764&r=nozend
MySQL Configuration Error:
http://bugs.php.net/fix.php?id=48764&r=mysqlcfg
