MYSQLND_QC_GET_CACHE_INFO(3)						 1					      MYSQLND_QC_GET_CACHE_INFO(3)

mysqlnd_qc_get_cache_info - Returns information on the current handler, the number of cache entries and cache entries, if available

SYNOPSIS

       array mysqlnd_qc_get_cache_info (void  )

DESCRIPTION

PARAMETERS

       This function has no parameters.

RETURN VALUES

	Returns information on the current handler, the number of cache entries and cache entries, if available. If and what data will be returned
       for the cache entries is subject to the active storage handler. Storage handler are free to return any data.  Storage  handler  are  recom-
       mended to return at least the data provided by the default handler, if technically possible.

	The scope of the information is the PHP process. Depending on the PHP deployment model a process may serve one or more web requests.

	Values	are  aggregated  for  all cache activities on a per storage handler basis. It is not possible to tell how much queries originating
       from mysqli, PDO_MySQL or mysql.API calls have contributed to the aggregated data values. Use mysqlnd_qc_get_core_stats(3)  to  get  timing
       data aggregated for all storage handlers.

	Array of cache information

	      o $handler
		string - The active storage handler.  All storage handler. Since 1.0.0.

	      o $handler_version
		string - The version of the active storage handler.  All storage handler. Since 1.0.0.

	      o $num_entries
		int  -	The number of cache entries. The value depends on the storage handler in use.  The default, APC and SQLite storage handler
		provide the actual number of cache entries.  The MEMCACHE storage handler always returns 0. MEMCACHE does not support counting the
		number of cache entries.  If a user defined handler is used, the number of entries of the data property is reported.  Since 1.0.0.

	      o $data
		array  -  The version of the active storage handler.  Additional storage handler dependent data on the cache entries. Storage han-
		dler are requested to provide similar and comparable information. A user defined storage handler  is  free  to	return	any  data.
		Since 1.0.0.  The following information is provided by the default storage handler for the data property.  The data property holds
		a hash. The hash is indexed by the internal cache entry identifier of the storage handler. The cache entry  identifier	is  human-
		readable and contains the query string leading to the cache entry. Please, see also the example below. The following data is given
		for every cache entry.

		     o $statistics
		       array - Statistics of the cache entry.  Since 1.0.0.

		     +---------------+--------------------------------------+---+
		     |	 Property    |					    |	|
		     |		     |					    |	|
		     |		     |		   Description		    |	|
		     |		     |					    |	|
		     |		     |		     Version		    |	|
		     |		     |					    |	|
		     +---------------+--------------------------------------+---+
		     |		     |					    |	|
		     |	   rows      |					    |	|
		     |		     |					    |	|
		     |		     |	Number of rows of the cached result |	|
		     |		     | set.				    |	|
		     |		     |					    |	|
		     |		     |		   Since 1.0.0. 	    |	|
		     |		     |					    |	|
		     |		     |					    |	|
		     | stored_size   |					    |	|
		     |		     |					    |	|
		     |		     |	The  size  of the cached result set |	|
		     |		     | in bytes. This is the  size  of	the |	|
		     |		     | payload. The value is not suited for |	|
		     |		     | calculating the	total  memory  con- |	|
		     |		     | sumption   of   all   cache  entries |	|
		     |		     | including the  administrative  over- |	|
		     |		     | head of the cache entries.	    |	|
		     |		     |					    |	|
		     |		     |		   Since 1.0.0. 	    |	|
		     |		     |					    |	|
		     |		     |					    |	|
		     |	cache_hits   |					    |	|
		     |		     |					    |	|
		     |		     |	How often the cached entry has been |	|
		     |		     | returned.			    |	|
		     |		     |					    |	|
		     |		     |		   Since 1.0.0. 	    |	|
		     |		     |					    |	|
		     |		     |					    |	|
		     |	 run_time    |					    |	|
		     |		     |					    |	|
		     |		     |	Run time of the statement to  which |	|
		     |		     | the cache entry belongs. This is the |	|
		     |		     | run time of the uncached  statement. |	|
		     |		     | It  is  the time between sending the |	|
		     |		     | statement to MySQL receiving a reply |	|
		     |		     | from  MySQL. Run time saved by using |	|
		     |		     | the query cache plugin can be calcu- |	|
		     |		     | lated   like   this:   cache_hits  * |	|
		     |		     | ((run_time   -	 avg_run_time)	  + |	|
		     |		     | (store_time - avg_store_time)).	    |	|
		     |		     |					    |	|
		     |		     |		   Since 1.0.0. 	    |	|
		     |		     |					    |	|
		     |		     |					    |	|
		     |	store_time   |					    |	|
		     |		     |					    |	|
		     |		     |	Store time of the statements result |	|
		     |		     | set  to	which	the   cache   entry |	|
		     |		     | belongs. This is the time it took to |	|
		     |		     | fetch and store the results  of	the |	|
		     |		     | uncached statement.		    |	|
		     |		     |					    |	|
		     |		     |		   Since 1.0.0. 	    |	|
		     |		     |					    |	|
		     |		     |					    |	|
		     | min_run_time  |					    |	|
		     |		     |					    |	|
		     |		     |	Minimum  run  time  of	the  cached |	|
		     |		     | statement. How long it took to  find |	|
		     |		     | the statement in the cache.	    |	|
		     |		     |					    |	|
		     |		     |		   Since 1.0.0. 	    |	|
		     |		     |					    |	|
		     |		     |					    |	|
		     |min_store_time |					    |	|
		     |		     |					    |	|
		     |		     |	Minimum  store	time  of the cached |	|
		     |		     | statement. The time taken for fetch- |	|
		     |		     | ing  the  cached result set from the |	|
		     |		     | storage medium and decoding	    |	|
		     |		     |					    |	|
		     |		     |		   Since 1.0.0. 	    |	|
		     |		     |					    |	|
		     |		     |					    |	|
		     | avg_run_time  |					    |	|
		     |		     |					    |	|
		     |		     |	Average  run  time  of	the  cached |	|
		     |		     | statement.			    |	|
		     |		     |					    |	|
		     |		     |		   Since 1.0.0. 	    |	|
		     |		     |					    |	|
		     |		     |					    |	|
		     |avg_store_time |					    |	|
		     |		     |					    |	|
		     |		     |	Average  store	time  of the cached |	|
		     |		     | statement.			    |	|
		     |		     |					    |	|
		     |		     |		   Since 1.0.0. 	    |	|
		     |		     |					    |	|
		     |		     |					    |	|
		     | max_run_time  |					    |	|
		     |		     |					    |	|
		     |		     |	Average  run  time  of	the  cached |	|
		     |		     | statement.			    |	|
		     |		     |					    |	|
		     |		     |		   Since 1.0.0. 	    |	|
		     |		     |					    |	|
		     |		     |					    |	|
		     |max_store_time |					    |	|
		     |		     |					    |	|
		     |		     |	Average  store	time  of the cached |	|
		     |		     | statement.			    |	|
		     |		     |					    |	|
		     |		     |		   Since 1.0.0. 	    |	|
		     |		     |					    |	|
		     |		     |					    |	|
		     | valid_until   |					    |	|
		     |		     |					    |	|
		     |		     |	Timestamp  when  the  cache   entry |	|
		     |		     | expires. 			    |	|
		     |		     |					    |	|
		     |		     |		   Since 1.1.0. 	    |	|
		     |		     |					    |	|
		     +---------------+--------------------------------------+---+
		     o $metadata
		       array  -  Metadata of the cache entry. This is the metadata provided by MySQL together with the result set of the statement
		       in question. Different versions of the MySQL server may return different metadata. Unlike with some of the PHP MySQL exten-
		       sions  no  attempt  is made to hide MySQL server version dependencies and version details from the caller. Please, refer to
		       the MySQL C API documentation that belongs to the MySQL server in use for further details.  The metadata list contains  one
		       entry for every column.	Since 1.0.0.

		     +-----------+--------------------------------------+---+
		     | Property  |					|   |
		     |		 |					|   |
		     |		 |	       Description		|   |
		     |		 |					|   |
		     |		 |		 Version		|   |
		     |		 |					|   |
		     +-----------+--------------------------------------+---+
		     |		 |					|   |
		     |	 name	 |					|   |
		     |		 |					|   |
		     |		 |  The  field	name.  Depending on the |   |
		     |		 | MySQL version this may be the fields |   |
		     |		 | alias name.				|   |
		     |		 |					|   |
		     |		 |	       Since 1.0.0.		|   |
		     |		 |					|   |
		     |		 |					|   |
		     | org_name  |					|   |
		     |		 |					|   |
		     |		 |	      The field name.		|   |
		     |		 |					|   |
		     |		 |	       Since 1.0.0.		|   |
		     |		 |					|   |
		     |		 |					|   |
		     |	table	 |					|   |
		     |		 |					|   |
		     |		 |  The  table	name.  If an alias name |   |
		     |		 | was used for the table, this usually |   |
		     |		 | holds the alias name.		|   |
		     |		 |					|   |
		     |		 |	       Since 1.0.0.		|   |
		     |		 |					|   |
		     |		 |					|   |
		     |org_table  |					|   |
		     |		 |					|   |
		     |		 |	      The table name.		|   |
		     |		 |					|   |
		     |		 |	       Since 1.0.0.		|   |
		     |		 |					|   |
		     |		 |					|   |
		     |	  db	 |					|   |
		     |		 |					|   |
		     |		 |	 The database/schema name.	|   |
		     |		 |					|   |
		     |		 |	       Since 1.0.0.		|   |
		     |		 |					|   |
		     |		 |					|   |
		     |max_length |					|   |
		     |		 |					|   |
		     |		 |  The  maximum  width  of  the field. |   |
		     |		 | Details may	vary  by  MySQL  server |   |
		     |		 | version.				|   |
		     |		 |					|   |
		     |		 |	       Since 1.0.0.		|   |
		     |		 |					|   |
		     |		 |					|   |
		     |	length	 |					|   |
		     |		 |					|   |
		     |		 |  The width of the field. Details may |   |
		     |		 | vary by MySQL server version.	|   |
		     |		 |					|   |
		     |		 |	       Since 1.0.0.		|   |
		     |		 |					|   |
		     |		 |					|   |
		     |	 type	 |					|   |
		     |		 |					|   |
		     |		 |  The data type of the field. Details |   |
		     |		 | may vary by the MySQL server in use. |   |
		     |		 | This is the MySQL C	API  type  con- |   |
		     |		 | stants  value.  It is recommended to |   |
		     |		 | use type constants provided	by  the |   |
		     |		 | mysqli  extension  to  test	for its |   |
		     |		 | meaning. You  should  not  test  for |   |
		     |		 | certain  type  values  by  comparing |   |
		     |		 | with certain numbers.		|   |
		     |		 |					|   |
		     |		 |	       Since 1.0.0.		|   |
		     |		 |					|   |
		     +-----------+--------------------------------------+---+
	       The APC storage handler returns the same information for the data property but no metadata. The metadata of a cache entry is set to
	      NULL.   The  MEMCACHE  storage handler does not fill the data property. Statistics are not available on a per cache entry basis with
	      the MEMCACHE storage handler.  A user defined storage handler is free to provide any data.

EXAMPLES

       Example #1

	      mysqlnd_qc_get_cache_info(3) example

	       The example shows the output from the built-in default storage handler. Other storage handler may report different data.

	      <?php
	      /* Populate the cache, e.g. using mysqli */
	      $mysqli = new mysqli("host", "user", "password", "schema");
	      $mysqli->query("/*" . MYSQLND_QC_ENABLE_SWITCH . "*/SELECT id FROM test");

	      /* Display cache information */
	      var_dump(mysqlnd_qc_get_cache_info());
	      ?>

	      The above examples will output:

	      array(4) {
	       ["num_entries"]=>
	       int(1)
	       ["handler"]=>
	       string(7) "default"
	       ["handler_version"]=>
	       string(5) "1.0.0"
	       ["data"]=>
	       array(1) {
		 ["Localhost via UNIX socket 3306 user schema|/*qc=on*/SELECT id FROM test"]=>
		 array(2) {
		   ["statistics"]=>
		   array(11) {
		     ["rows"]=>
		     int(6)
		     ["stored_size"]=>
		     int(101)
		     ["cache_hits"]=>
		     int(0)
		     ["run_time"]=>
		     int(471)
		     ["store_time"]=>
		     int(27)
		     ["min_run_time"]=>
		     int(0)
		     ["max_run_time"]=>
		     int(0)
		     ["min_store_time"]=>
		     int(0)
		     ["max_store_time"]=>
		     int(0)
		     ["avg_run_time"]=>
		     int(0)
		     ["avg_store_time"]=>
		     int(0)
		   }
		   ["metadata"]=>
		   array(1) {
		     [0]=>
		     array(8) {
		       ["name"]=>
		       string(2) "id"
		       ["orig_name"]=>
		       string(2) "id"
		       ["table"]=>
		       string(4) "test"
		       ["orig_table"]=>
		       string(4) "test"
		       ["db"]=>
		       string(4) "schema"
		       ["max_length"]=>
		       int(1)
		       ["length"]=>
		       int(11)
		       ["type"]=>
		       int(3)
		     }
		   }
		 }
	       }
	      }

SEE ALSO

       mysqlnd_qc_get_core_stats(3).

PHP Documentation Group 											      MYSQLND_QC_GET_CACHE_INFO(3)