(PECL mysqlnd_qc >= 1.0.0)
mysqlnd_qc_get_available_handlers — Returns a list of available storage handler
   Which storage are available depends on the compile time
   configuration of the query cache plugin. The
   default storage handler is always available.
   All other storage handler must be enabled explicitly when building the
   extension.
  
此函数没有参数。
Returns an array of available built-in storage handler. For each storage handler the version number and version string is given.
Example #1 mysqlnd_qc_get_available_handlers() example
<?php
var_dump(mysqlnd_qc_get_available_handlers());
?>
以上例程会输出:
array(5) {
  ["default"]=>
  array(2) {
    ["version"]=>
    string(5) "1.0.0"
    ["version_number"]=>
    int(100000)
  }
  ["user"]=>
  array(2) {
    ["version"]=>
    string(5) "1.0.0"
    ["version_number"]=>
    int(100000)
  }
  ["APC"]=>
  array(2) {
    ["version"]=>
    string(5) "1.0.0"
    ["version_number"]=>
    int(100000)
  }
  ["MEMCACHE"]=>
  array(2) {
    ["version"]=>
    string(5) "1.0.0"
    ["version_number"]=>
    int(100000)
  }
  ["sqlite"]=>
  array(2) {
    ["version"]=>
    string(5) "1.0.0"
    ["version_number"]=>
    int(100000)
  }
}