mysqlnd_ms_query_is_select(3) [php man page]

MYSQLND_MS_QUERY_IS_SELECT(3)						 1					     MYSQLND_MS_QUERY_IS_SELECT(3)

mysqlnd_ms_query_is_select - Find whether to send the query to the master, the slave or the last used MySQL server

SYNOPSIS

       int mysqlnd_ms_query_is_select (string  $query)

DESCRIPTION

	Finds whether to send the query to the master, the slave or the last used MySQL server.

	The plugins built-in read/write split mechanism will be used to analyze the query string to make a recommendation where to send the query.
       The built-in read/write split mechanism is very basic and simple. The plugin will recommend sending all queries to  the	MySQL  replication
       master  server  but  those which begin with SELECT, or begin with a SQL hint which enforces sending the query to a slave server. Due to the
       basic but fast algorithm the plugin may propose to run some read-only statements such as SHOW TABLES on the replication master.

PARAMETERS

	      o $query
		- Query string to test.

RETURN VALUES

	A return value of MYSQLND_MS_QUERY_USE_MASTER indicates that the query should be send to the MySQL replication master server. The function
       returns	a  value  of  MYSQLND_MS_QUERY_USE_SLAVE  if  the  query  can  be  run	on  a slave because it is considered read-only. A value of
       MYSQLND_MS_QUERY_USE_LAST_USED is returned to recommend running the query on the last used server. This can either be a	MySQL  replication
       master server or a MySQL replication slave server.

	If   read   write   splitting	has   been   disabled	by   setting   mysqlnd_ms.disable_rw_split,   the   function  will  always  return
       MYSQLND_MS_QUERY_USE_MASTER or MYSQLND_MS_QUERY_USE_LAST_USED.

EXAMPLES

       Example #1

	      mysqlnd_ms_query_is_select(3) example

	      <?php
	      function is_select($query)
	      {
	       switch (mysqlnd_ms_query_is_select($query))
	       {
		case MYSQLND_MS_QUERY_USE_MASTER:
		 printf("'%s' should be run on the master.
", $query);
		 break;
		case MYSQLND_MS_QUERY_USE_SLAVE:
		 printf("'%s' should be run on a slave.
", $query);
		 break;
		case MYSQLND_MS_QUERY_USE_LAST_USED:
		 printf("'%s' should be run on the server that has run the previous query
", $query);
		 break;
		default:
		 printf("No suggestion where to run the '%s', fallback to master recommended
", $query);
		 break;
	       }
	      }

	      is_select("INSERT INTO test(id) VALUES (1)");
	      is_select("SELECT 1 FROM DUAL");
	      is_select("/*" . MYSQLND_MS_LAST_USED_SWITCH . "*/SELECT 2 FROM DUAL");
	      ?>

	      The above example will output:

	      INSERT INTO test(id) VALUES (1) should be run on the master.
	      SELECT 1 FROM DUAL should be run on a slave.
	      /*ms=last_used*/SELECT 2 FROM DUAL should be run on the server that has run the previous query

SEE ALSO

       Predefined Constants, user filter .Runtime configuration, mysqlnd_ms.disable_rw_split, mysqlnd_ms.enable.

PHP Documentation Group 											     MYSQLND_MS_QUERY_IS_SELECT(3)

MYSQLND_MEMCACHE_SET(3) 						 1						   MYSQLND_MEMCACHE_SET(3)

mysqlnd_memcache_set - Associate a MySQL connection with a Memcache connection

SYNOPSIS

       bool mysqlnd_memcache_set (mixed  $mysql_connection, [Memcached	$memcache_connection], [string	$pattern], [callback  $callback])

DESCRIPTION

	Associate  $mysql_connection  with $memcache_connection using $pattern as a PCRE regular expression, and $callback as a notification call-
       back or to unset the association of $mysql_connection.

	While associating a MySQL connection with a Memcache connection, this function will query the MySQL Server for its configuration. It  will
       automatically  detect  whether  the server is configured to use the InnoDB Memcache Daemon Plugin or MySQL Cluster NDB Memcache support. It
       will also query the server to automatically identify exported tables and other configuration options. The results of this automatic config-
       uration can be retrieved using mysqlnd_memcache_get_config(3).

PARAMETERS

	      o $mysql_connection
		- A handle to a MySQL Server using one of the MySQL API extensions for PHP, which are PDO_MYSQL, mysqli or ext/mysql.

	      o $memcache_connection
		- A Memcached instance with a connection to the MySQL Memcache Daemon plugin. If this parameter is omitted, then $mysql_connection
		will be unassociated from any memcache connection. And if a previous association exists, then it will be replaced.

	      o $pattern
		- A regular expression in Perl Compatible Regular Expression syntax used to identify potential Memcache-queries. The query  should
		have  three  sub  patterns.  The first subpattern contains the requested field list, the second the name of the ID column from the
		query and the third the requested value. If this parameter is omitted or os set to NULL, then a default pattern will be used.

	      o $callback
		- A callback which will be used whenever a query is being sent to MySQL. The callback will  receive  a	single	boolean  parameter
		telling if a query was sent via Memcache.

RETURN VALUES

       TRUE if the association or disassociation is successful, otherwise FALSE if there is an error.

EXAMPLES

       Example #1

	      mysqlnd_memcache_set(3) example with var_dump(3) as a simple debugging callback.

	      <?php
	      $mysqli = new mysqli("host", "user", "passwd", "database");
	      $memc = new Memcached();
	      $memc->addServer("host", 11211);
	      mysqlnd_memcache_set($mysqli, $memc, NULL, 'var_dump');

	      /* This query will be intercepted and executed via Memcache protocol */
	      echo "Sending query for id via Memcache: ";
	      $mysqli->query("SELECT f1, f2, f3 FROM test WHERE id = 1");

	      /* f1 is not configured as valid key field, this won't be sent via Memcache */
	      echo "Sending query for f1 via Memcache: ";
	      $mysqli->query("SELECT id FROM test WHERE f1 = 1");

	      mysqlnd_memcache_set($mysqli);

	      /* Now the regular MySQL protocol will be used */
	      echo "var_dump won't be invoked: ";
	      $mysqli->query("SELECT f1, f2, f3 WHERE id = 1");

	      ?>

	      The above example will output:

	      Sending query for id via Memcache: bool(true)
	      Sending query for f1 via Memcache: bool(false)
	      var_dump won't be invoked:

SEE ALSO

       mysqlnd_memcache_get_config(3).

PHP Documentation Group 												   MYSQLND_MEMCACHE_SET(3)