#48764 [Opn]: PDO_pgsql::query always uses implicit prepared statements if v3 proto available
ID: 48764
User updated by: mark dot kirkwood at catalyst dot net dot nz
Reported By: mark dot kirkwood at catalyst dot net dot nz
Status: Open
Bug Type: PDO related
Operating System: Linux 2.6.28 (Ubuntu) amd64
PHP Version: 5.3CVS-2009-07-01 (snap)
New Comment:
diff -Nacr php5.2-200906300830/ext/pdo_pgsql/pdo_pgsql.c
php5.2-200906300830.mod/ext/pdo_pgsql/pdo_pgsql.c
*** php5.2-200906300830/ext/pdo_pgsql/pdo_pgsql.c Thu Jan 1 00:46:35
2009
--- php5.2-200906300830.mod/ext/pdo_pgsql/pdo_pgsql.c Wed Jul 1
23:51:24 2009
***************
*** 80,87 ****
*/
PHP_MINIT_FUNCTION(pdo_pgsql)
{
- php_pdo_register_driver(&pdo_pgsql_driver);
REGISTER_PDO_CLASS_CONST_LONG("PGSQL_ATTR_DISABLE_NATIVE_PREPARED_STATEMENT",
PDO_PGSQL_ATTR_DISABLE_NATIVE_PREPARED_STATEMENT);
return SUCCESS;
}
/* }}} */
--- 80,87 ----
*/
PHP_MINIT_FUNCTION(pdo_pgsql)
{
REGISTER_PDO_CLASS_CONST_LONG("PGSQL_ATTR_DISABLE_NATIVE_PREPARED_STATEMENT",
PDO_PGSQL_ATTR_DISABLE_NATIVE_PREPARED_STATEMENT);
+ php_pdo_register_driver(&pdo_pgsql_driver);
return SUCCESS;
}
/* }}} */
diff -Nacr php5.2-200906300830/ext/pdo_pgsql/pgsql_driver.c
php5.2-200906300830.mod/ext/pdo_pgsql/pgsql_driver.c
*** php5.2-200906300830/ext/pdo_pgsql/pgsql_driver.c Thu Jan 1
00:46:35 2009
--- php5.2-200906300830.mod/ext/pdo_pgsql/pgsql_driver.c Thu Jul 2
00:06:20 2009
***************
*** 248,253 ****
--- 248,257 ----
}
}
+ if (H->emulate == 1) {
+ emulate = 1;
+ }
+
if (!emulate && PQprotocolVersion(H->server) > 2) {
stmt->supports_placeholders = PDO_PLACEHOLDER_NAMED;
stmt->named_rewrite_template = "$%d";
***************
*** 646,652 ****
static int pdo_pgsql_set_attr(pdo_dbh_t *dbh, long attr, zval *val
TSRMLS_DC)
{
! return 0;
}
static struct pdo_dbh_methods pgsql_methods = {
--- 650,663 ----
static int pdo_pgsql_set_attr(pdo_dbh_t *dbh, long attr, zval *val
TSRMLS_DC)
{
! switch (attr) {
! convert_to_boolean(val);
! case PDO_PGSQL_ATTR_DISABLE_NATIVE_PREPARED_STATEMENT:
! ((pdo_pgsql_db_handle *)dbh->driver_data)->emulate =
Z_BVAL_P(val);
! return 1;
! default:
! return 0;
! }
}
static struct pdo_dbh_methods pgsql_methods = {
diff -Nacr php5.2-200906300830/ext/pdo_pgsql/php_pdo_pgsql_int.h
php5.2-200906300830.mod/ext/pdo_pgsql/php_pdo_pgsql_int.h
*** php5.2-200906300830/ext/pdo_pgsql/php_pdo_pgsql_int.h Thu Jan 1
00:46:35 2009
--- php5.2-200906300830.mod/ext/pdo_pgsql/php_pdo_pgsql_int.h Wed Jul
1 23:55:50 2009
***************
*** 40,45 ****
--- 40,46 ----
typedef struct {
PGconn *server;
unsigned attached:1;
+ unsigned emulate:1;
unsigned _reserved:31;
pdo_pgsql_error_info einfo;
Oid pgoid;
Previous Comments:
------------------------------------------------------------------------
[2009-07-01 23:50:08] mark dot kirkwood at catalyst dot net dot nz
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 this bug report at http://bugs.php.net/?id=48764&edit=1
Thread (6 messages)