8.11.4.2 Usage

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After associating a MySQL connection with a Memcache connection using mysqnd_memcache_set the plugin attempts to transparently replace SQL SELECT statements by a memcache access. For that purpose the plugin monitors all SQL statements executed and tries to match the statement string against MYSQLND_MEMCACHE_DEFAULT_REGEXP. In case of a match, the mysqlnd memcache plugin checks whether the SELECT is accessing only columns of a mapped table and the WHERE clause is limited to a single key lookup.

In case of the example SQL table, the plugin will use the Memcache interface of the MySQL server to fetch results for a SQL query like SELECT f1, f2, f3 WHERE id = n.

Example 8.397 Basic example.

<?php
$mysqli = new mysqli("host", "user", "passwd", "database");
$memc = new Memcached();
$memc->addServer("host", 11211);
mysqlnd_memcache_set($mysqli, $memc);
/*
   This is a query which queries table test using id as key in the WHERE part
   and is accessing fields f1, f2 and f3. Therefore, mysqlnd_memcache
   will intercept it and route it via memcache.
*/
$result = $mysqli->query("SELECT f1, f2, f3 FROM test WHERE id = 1");
while ($row = $result->fetch_row()) {
    print_r($row);
}
/*
   This is a query which queries table test but using f1 in the WHERE clause.
   Therefore, mysqlnd_memcache can't intercept it. This will be executed
   using the MySQL protocol
*/
$mysqli->query("SELECT id FROM test WHERE f1 = 'Lady'");
while ($row = $result->fetch_row()) {
    print_r($row);
}
?>

The above example will output:

array(
    [f1] => Hello
    [f2] => World
    [f3] => !
)
array(
    [id] => 2
)