Is PDO incompatible with caching mechanismes like APC?

[Gilles Ganault]

Hi

APC doesn't like it when I store the output of a SELECT:

===
include("apc.php");

$dbh = new PDO("sqlite:./test.sqlite");

$sql = "CREATE TABLE IF NOT EXISTS mytable (name TEXT)";
$dbh->exec($sql);

$sql = "INSERT INTO mytable VALUES (?)";
$insert = $dbh->prepare($sql);
$insert->execute(array("dead"));

$sql = "INSERT INTO mytable VALUES (?)";
$insert = $dbh->prepare($sql);
$insert->execute(array("beef"));

$sql = "SELECT * FROM mytable";
store("rows",$dbh->query($sql));

$rows = fetch("rows");
foreach($rows as $row) {
print $row['name'] . "<p>";
}

$dbh = null;
===
PHP Fatal error: Uncaught exception 'PDOException' with message 'You
cannot serialize or unserialize PDOStatement instances' in
/usr/local/www/apache22/data/apc.php:9\nStack trace:\n#0 [internal
function]: PDOStatement->__sleep()\n#1
/usr/local/www/apache22/data/apc.php(9): apc_store('rows',
Object(PDOStatement), 0)\n#2
/usr/local/www/apache22/data/test.php(21): store('rows',
Object(PDOStatement))\n#3 {main}\n thrown in
/usr/local/www/apache22/data/apc.php on line 9
===

Does it mean that PDO won't work with APC, and I should look at
another caching tool?

Thank you.

[Gilles Ganault]

On Sat, 29 Mar 2008 20:54:08 -0700, Jeremy <je****@pinacol.comwrote:

>It seems like what you want to do is store an array of the rows, which
is perfectly possible. Just use $dbh->query(...)->fetchAll() or
something similar.

Thanks for the tip. This code works:

$sql = "SELECT * FROM mytable";
$sth = $dbh->prepare($sql);
$sth->execute();
store("rows",$sth->fetchAll());

$rows = fetch("rows");
foreach($rows as $row) {
print $row['name'] . "<p>";
}

[Gilles Ganault]

On Sun, 30 Mar 2008 13:26:45 +0200, Gilles Ganault <no****@nospam.com>
wrote:

>Thanks for the tip. This code works:

It works, but according to "ab", it's much slower to use APC than
hitting the SQLite file directly :-/

========
# ab -kc 10 -t 30 http://localhost/test_apc.php

Percentage of the requests served within a certain time (ms)
50% 105
66% 1054
75% 2066
80% 3089
90% 4347
95% 8136
98% 10140
99% 12148
100% 13115 (longest request)
========
# ab -kc 10 -t 30 http://192.168.0.2/test_direct.php

Percentage of the requests served within a certain time (ms)
50% 29
66% 30
75% 31
80% 32
90% 2038
95% 6072
98% 14049
99% 17056
100% 17199 (longest request)
========

Does APC start making sense with a lot more users, or is SQLite just
much faster than MySQL?

[Jerry Stuckle]

Gilles Ganault wrote:

On Sun, 30 Mar 2008 13:26:45 +0200, Gilles Ganault <no****@nospam.com>
wrote:

>Thanks for the tip. This code works:

It works, but according to "ab", it's much slower to use APC than
hitting the SQLite file directly :-/

========
# ab -kc 10 -t 30 http://localhost/test_apc.php

Percentage of the requests served within a certain time (ms)
50% 105
66% 1054
75% 2066
80% 3089
90% 4347
95% 8136
98% 10140
99% 12148
100% 13115 (longest request)
========
# ab -kc 10 -t 30 http://192.168.0.2/test_direct.php

Percentage of the requests served within a certain time (ms)
50% 29
66% 30
75% 31
80% 32
90% 2038
95% 6072
98% 14049
99% 17056
100% 17199 (longest request)
========

Does APC start making sense with a lot more users, or is SQLite just
much faster than MySQL?

This is off topic in this newsgroup.
--
==================
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Jerry Stuckle
JDS Computer Training Corp.
js*******@attglobal.net
==================