Oracle 5.0 Reference Manual page 2683

Mysqlnd query result cache plugin (mysqlnd_qc)
<?php
/* Connect, create and populate test table */
$mysqli = new mysqli("host", "user", "password", "schema", "port", "socket");
$mysqli->query("DROP TABLE IF EXISTS test");
$mysqli->query("CREATE TABLE test(id INT)");
$mysqli->query("INSERT INTO test(id) VALUES (1)");
for ($i = 0; $i < 3; $i++) {
$start = microtime(true);
/* Note: statement will not be cached because of NOW() use */
$res = $mysqli->query("SELECT id, NOW() AS _time FROM test");
$row = $res->fetch_assoc();
/* dump results */
var_dump($row);
printf("Total time: %.6fs\n", microtime(true) - $start);
/* pause one second */
sleep(1);
}
?>
The above examples will output something similar to:
array(2) {
["id"]=>
string(1) "1"
["_time"]=>
string(19) "2012-01-11 15:43:10"
}
Total time: 0.000540s
array(2) {
["id"]=>
string(1) "1"
["_time"]=>
string(19) "2012-01-11 15:43:11"
}
Total time: 0.000555s
array(2) {
["id"]=>
string(1) "1"
["_time"]=>
string(19) "2012-01-11 15:43:12"
}
Total time: 0.000549s
It is possible to enable caching for all statements including those which has columns in their
result set for which MySQL reports no table, such as the statement from the example. Set
mysqlnd_qc.cache_no_table = 1
difference in the measured times for the above and below examples.
Example 20.308. Enabling caching for all statements using the
ini setting
mysqlnd_qc.enable_qc=1
mysqlnd_qc.cache_by_default=1
mysqlnd_qc.cache_no_table=1
to enable caching of such statements. Please, note the
2663
mysqlnd_qc.cache_no_table