<?php
var_dump(mysqlnd_qc_get_available_handlers());
?>

   

The above examples will output:

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)
  }
}

   

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)
       }
     }
   }
 }
}


   

<?php
/* Enable collection of statistics - default: disabled */
ini_set("mysqlnd_qc.collect_statistics", 1);

/* Enable collection of all timing related statistics -
default: enabled but overruled by mysqlnd_qc.collect_statistics = 0 */
ini_set("mysqlnd_qc.collect_time_statistics", 1);

/* Populate the cache, e.g. using mysqli */
$mysqli = new mysqli('host', 'user', 'password', 'schema');

/* Cache miss and cache put */
$mysqli->query("/*qc=on*/SELECT id FROM test");
/* Cache hit */
$mysqli->query("/*qc=on*/SELECT id FROM test");

/* Display core statistics */
var_dump(mysqlnd_qc_get_core_stats());
?>

   

The above examples will output:

array(26) {
  ["cache_hit"]=>
  string(1) "1"
  ["cache_miss"]=>
  string(1) "1"
  ["cache_put"]=>
  string(1) "1"
  ["query_should_cache"]=>
  string(1) "2"
  ["query_should_not_cache"]=>
  string(1) "0"
  ["query_not_cached"]=>
  string(1) "0"
  ["query_could_cache"]=>
  string(1) "2"
  ["query_found_in_cache"]=>
  string(1) "1"
  ["query_uncached_other"]=>
  string(1) "0"
  ["query_uncached_no_table"]=>
  string(1) "0"
  ["query_uncached_no_result"]=>
  string(1) "0"
  ["query_uncached_use_result"]=>
  string(1) "0"
  ["query_aggr_run_time_cache_hit"]=>
  string(1) "4"
  ["query_aggr_run_time_cache_put"]=>
  string(3) "395"
  ["query_aggr_run_time_total"]=>
  string(3) "399"
  ["query_aggr_store_time_cache_hit"]=>
  string(1) "2"
  ["query_aggr_store_time_cache_put"]=>
  string(1) "8"
  ["query_aggr_store_time_total"]=>
  string(2) "10"
  ["receive_bytes_recorded"]=>
  string(2) "65"
  ["receive_bytes_replayed"]=>
  string(2) "65"
  ["send_bytes_recorded"]=>
  string(2) "29"
  ["send_bytes_replayed"]=>
  string(2) "29"
  ["slam_stale_refresh"]=>
  string(1) "0"
  ["slam_stale_hit"]=>
  string(1) "0"
  ["request_counter"]=>
  int(1)
  ["process_hash"]=>
  int(3547549858)
}


   

mysqlnd_qc.collect_normalized_query_trace=1

   

<?php
/* Connect, create and populate test table */
$mysqli = new mysqli("host", "user", "password", "schema", "port", "socket");
$mysqli->query("DROP TABLE IF EXISTS test");
$mysqli->query("CREATE TABLE test(id INT)");
$mysqli->query("INSERT INTO test(id) VALUES (1), (2)");

/* not cached */
$res = $mysqli->query("SELECT id FROM test WHERE id = 1");
var_dump($res->fetch_assoc());
$res->free();

/* cache put */
$res = $mysqli->query("/*" . MYSQLND_QC_ENABLE_SWITCH . "*/" . "SELECT id FROM test WHERE id = 2");
var_dump($res->fetch_assoc());
$res->free();

/* cache hit */
$res = $mysqli->query("/*" . MYSQLND_QC_ENABLE_SWITCH . "*/" . "SELECT id FROM test WHERE id = 2");
var_dump($res->fetch_assoc());
$res->free();

var_dump(mysqlnd_qc_get_normalized_query_trace_log());
?>

   

The above examples will output:

array(1) {
  ["id"]=>
  string(1) "1"
}
array(1) {
  ["id"]=>
  string(1) "2"
}
array(1) {
  ["id"]=>
  string(1) "2"
}
array(4) {
  [0]=>
  array(9) {
    ["query"]=>
    string(25) "DROP TABLE IF EXISTS test"
    ["occurences"]=>
    int(0)
    ["eligible_for_caching"]=>
    bool(false)
    ["avg_run_time"]=>
    int(0)
    ["min_run_time"]=>
    int(0)
    ["max_run_time"]=>
    int(0)
    ["avg_store_time"]=>
    int(0)
    ["min_store_time"]=>
    int(0)
    ["max_store_time"]=>
    int(0)
  }
  [1]=>
  array(9) {
    ["query"]=>
    string(27) "CREATE TABLE test (id INT )"
    ["occurences"]=>
    int(0)
    ["eligible_for_caching"]=>
    bool(false)
    ["avg_run_time"]=>
    int(0)
    ["min_run_time"]=>
    int(0)
    ["max_run_time"]=>
    int(0)
    ["avg_store_time"]=>
    int(0)
    ["min_store_time"]=>
    int(0)
    ["max_store_time"]=>
    int(0)
  }
  [2]=>
  array(9) {
    ["query"]=>
    string(40) "INSERT INTO test (id ) VALUES (? ), (? )"
    ["occurences"]=>
    int(0)
    ["eligible_for_caching"]=>
    bool(false)
    ["avg_run_time"]=>
    int(0)
    ["min_run_time"]=>
    int(0)
    ["max_run_time"]=>
    int(0)
    ["avg_store_time"]=>
    int(0)
    ["min_store_time"]=>
    int(0)
    ["max_store_time"]=>
    int(0)
  }
  [3]=>
  array(9) {
    ["query"]=>
    string(31) "SELECT id FROM test WHERE id =?"
    ["occurences"]=>
    int(2)
    ["eligible_for_caching"]=>
    bool(true)
    ["avg_run_time"]=>
    int(159)
    ["min_run_time"]=>
    int(12)
    ["max_run_time"]=>
    int(307)
    ["avg_store_time"]=>
    int(10)
    ["min_store_time"]=>
    int(8)
    ["max_store_time"]=>
    int(13)
  }
}

   

mysqlnd_qc.collect_query_trace=1

   

<?php
/* Connect, create and populate test table */
$mysqli = new mysqli("host", "user", "password", "schema", "port", "socket");
$mysqli->query("DROP TABLE IF EXISTS test");
$mysqli->query("CREATE TABLE test(id INT)");
$mysqli->query("INSERT INTO test(id) VALUES (1), (2)");

/* not cached */
$res = $mysqli->query("SELECT id FROM test WHERE id = 1");
var_dump($res->fetch_assoc());
$res->free();

/* cache put */
$res = $mysqli->query("/*" . MYSQLND_QC_ENABLE_SWITCH . "*/" . "SELECT id FROM test WHERE id = 2");
var_dump($res->fetch_assoc());
$res->free();

/* cache hit */
$res = $mysqli->query("/*" . MYSQLND_QC_ENABLE_SWITCH . "*/" . "SELECT id FROM test WHERE id = 2");
var_dump($res->fetch_assoc());
$res->free();

var_dump(mysqlnd_qc_get_query_trace_log());
?>

   

The above examples will output:

array(1) {
  ["id"]=>
  string(1) "1"
}
array(1) {
  ["id"]=>
  string(1) "2"
}
array(1) {
  ["id"]=>
  string(1) "2"
}
array(6) {
  [0]=>
  array(8) {
    ["query"]=>
    string(25) "DROP TABLE IF EXISTS test"
    ["origin"]=>
    string(102) "#0 qc.php(4): mysqli->query('DROP TABLE IF E...')
#1 {main}"
    ["run_time"]=>
    int(0)
    ["store_time"]=>
    int(0)
    ["eligible_for_caching"]=>
    bool(false)
    ["no_table"]=>
    bool(false)
    ["was_added"]=>
    bool(false)
    ["was_already_in_cache"]=>
    bool(false)
  }
  [1]=>
  array(8) {
    ["query"]=>
    string(25) "CREATE TABLE test(id INT)"
    ["origin"]=>
    string(102) "#0 qc.php(5): mysqli->query('CREATE TABLE te...')
#1 {main}"
    ["run_time"]=>
    int(0)
    ["store_time"]=>
    int(0)
    ["eligible_for_caching"]=>
    bool(false)
    ["no_table"]=>
    bool(false)
    ["was_added"]=>
    bool(false)
    ["was_already_in_cache"]=>
    bool(false)
  }
  [2]=>
  array(8) {
    ["query"]=>
    string(36) "INSERT INTO test(id) VALUES (1), (2)"
    ["origin"]=>
    string(102) "#0 qc.php(6): mysqli->query('INSERT INTO tes...')
#1 {main}"
    ["run_time"]=>
    int(0)
    ["store_time"]=>
    int(0)
    ["eligible_for_caching"]=>
    bool(false)
    ["no_table"]=>
    bool(false)
    ["was_added"]=>
    bool(false)
    ["was_already_in_cache"]=>
    bool(false)
  }
  [3]=>
  array(8) {
    ["query"]=>
    string(32) "SELECT id FROM test WHERE id = 1"
    ["origin"]=>
    string(102) "#0 qc.php(9): mysqli->query('SELECT id FROM ...')
#1 {main}"
    ["run_time"]=>
    int(0)
    ["store_time"]=>
    int(25)
    ["eligible_for_caching"]=>
    bool(false)
    ["no_table"]=>
    bool(false)
    ["was_added"]=>
    bool(false)
    ["was_already_in_cache"]=>
    bool(false)
  }
  [4]=>
  array(8) {
    ["query"]=>
    string(41) "/*qc=on*/SELECT id FROM test WHERE id = 2"
    ["origin"]=>
    string(103) "#0 qc.php(14): mysqli->query('/*qc=on*/SELECT...')
#1 {main}"
    ["run_time"]=>
    int(311)
    ["store_time"]=>
    int(13)
    ["eligible_for_caching"]=>
    bool(true)
    ["no_table"]=>
    bool(false)
    ["was_added"]=>
    bool(true)
    ["was_already_in_cache"]=>
    bool(false)
  }
  [5]=>
  array(8) {
    ["query"]=>
    string(41) "/*qc=on*/SELECT id FROM test WHERE id = 2"
    ["origin"]=>
    string(103) "#0 qc.php(19): mysqli->query('/*qc=on*/SELECT...')
#1 {main}"
    ["run_time"]=>
    int(13)
    ["store_time"]=>
    int(8)
    ["eligible_for_caching"]=>
    bool(true)
    ["no_table"]=>
    bool(false)
    ["was_added"]=>
    bool(false)
    ["was_already_in_cache"]=>
    bool(true)
  }
}

   

<?php
/* Cache all accesses to tables with the name "new%" in schema/database "db_example" for 1 second */
if (!mysqlnd_qc_set_cache_condition(MYSQLND_QC_CONDITION_META_SCHEMA_PATTERN, "db_example.new%", 1)) {
  die("Failed to set cache condition!");
}

$mysqli = new mysqli("host", "user", "password", "db_example", "port");
/* cached although no SQL hint given  */
$mysqli->query("SELECT id, title FROM news");

$pdo_mysql = new PDO("mysql:host=host;dbname=db_example;port=port", "user", "password");
/* not cached: no SQL hint, no pattern match */
$pdo_mysql->query("SELECT id, title FROM latest_news");
/* cached: TTL 1 second, pattern match */
$pdo_mysql->query("SELECT id, title FROM news");
?>

   

<?php
/* callback which decides if query is cached */
function is_select($query) {
  static $patterns = array(
   /* true - use default from mysqlnd_qc.ttl */
   "@SELECT\s+.*\s+FROM\s+test@ismU" => true,
   /* 3 - use TTL = 3 seconds */
   "@SELECT\s+.*\s+FROM\s+news@ismU" => 3
  );
  /* check if query does match pattern */
  foreach ($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");
?>

   

The above examples will output:

is_select(                    DROP TABLE IF EXISTS test): do not cache
is_select(                    CREATE TABLE test(id INT)): do not cache
is_select(    INSERT INTO test(id) VALUES (1), (2), (3)): do not cache
is_select(             SELECT id FROM test WHERE id = 1): cache
is_select(             SELECT id FROM test WHERE id = 1): cache
is_select(                           SELECT * FROM test): cache

   

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

<?php
var_dump(mysqlnd_qc_set_storage_handler("memcache"));

if (true === mysqlnd_qc_set_storage_handler("default"))
  printf("Default storage handler activated");

/* Catchable fatal error */
var_dump(mysqlnd_qc_set_storage_handler("unknown"));
?>

   

The above examples will output:

bool(true)
Default storage handler activated
Catchable fatal error: mysqlnd_qc_set_storage_handler(): Unknown handler 'unknown' in (file) on line (line)