mysqlnd_qc_set_is_select Installs a callback which decides whether a statement is cached &reftitle.description; mixed mysqlnd_qc_set_is_select string callback Installs a callback which decides whether a statement is cached. There are several ways of hinting PELC/mysqlnd_qc to cache a query. By default, PECL/mysqlnd_qc attempts to cache a if caching of all statements is enabled or the query string begins with a certain SQL hint. The plugin internally calls a function named is_select() to find out. This internal function can be replaced with a user-defined callback. Then, the user-defined callback is responsible to decide whether the plugin attempts to cache a statement. Because the internal function is replaced with the callback, the callback gains full control. The callback is free to ignore the configuration setting mysqlnd_qc.cache_by_default and SQL hints. The callback is invoked for every statement inspected by the plugin. It is given the statements string as a parameter. The callback returns &false; if the statement shall not be cached. It returns &true; to make the plugin attempt to cache the statements result set, if any. A so-created cache entry is given the default TTL set with the PHP configuration directive mysqlnd_qc.ttl. If a different TTL shall be used, the callback returns a numeric value to be used as the TTL. The internal is_select function is part of the internal cache storage handler interface. Thus, a user-defined storage handler offers the same capabilities. &reftitle.parameters; &no.function.parameters; &reftitle.returnvalues; &return.success; &reftitle.examples; true, /* 3 - use TTL = 3 seconds */ "@SELECT\s+.*\s+FROM\s+news@ismU" => 3 ); /* check if query does match pattern */ foreach ($patterns as $pattern => $ttl) { if (preg_match($pattern, $query)) { printf("is_select(%45s): cache\n", $query); return $ttl; } } printf("is_select(%45s): do not cache\n", $query); return false; } mysqlnd_qc_set_is_select("is_select"); /* Connect, create and populate test table */ $mysqli = new mysqli("host", "user", "password", "schema"); $mysqli->query("DROP TABLE IF EXISTS test"); $mysqli->query("CREATE TABLE test(id INT)"); $mysqli->query("INSERT INTO test(id) VALUES (1), (2), (3)"); /* cache put */ $mysqli->query("SELECT id FROM test WHERE id = 1"); /* cache hit */ $mysqli->query("SELECT id FROM test WHERE id = 1"); /* cache put */ $mysqli->query("SELECT * FROM test"); ?> ]]> &examples.outputs; &reftitle.seealso; Runtime configuration mysqlnd_qc.ttl mysqlnd_qc.cache_by_default mysqlnd_qc_set_user_handlers