(PECL mysqlnd_qc >= 1.0.0)
mysqlnd_qc_get_query_trace_log — Returns a backtrace for each query inspected by the query cache
Returns a backtrace for each query inspected by the query cache.
The collection of the backtrace is disabled by default. To collect
the backtrace you have to set the PHP configuration directive
mysqlnd_qc.collect_query_trace
to
1
The maximum depth of the backtrace is limited to the depth set
with the PHP configuration directive
mysqlnd_qc.query_trace_bt_depth
.
Diese Funktion besitzt keine Parameter.
An array of query backtrace. Every list entry contains the query string, a backtrace and further detail information.
Key | Description |
---|---|
query
|
Query string. |
origin
|
Code backtrace. |
run_time
|
Query run time in milliseconds. The collection of
all times and the necessary
gettimeofday
system calls can be disabled by setting the PHP configuration
directive
mysqlnd_qc.time_statistics to
0
|
store_time
|
Query result set store time in milliseconds. The collection of
all times and the necessary
gettimeofday
system calls can be disabled by setting the PHP configuration
directive
mysqlnd_qc.time_statistics to
0
|
eligible_for_caching
|
true if query is cacheable otherwise
false .
|
no_table
|
true if the query has generated a result
set and at least one column from the result set has no table
name set in its metadata. This is usually the case with
queries which one probably do not want to cache such as
SELECT SLEEP(1) . By default any such query
will not be added to the cache. See also PHP configuration directive
mysqlnd_qc.cache_no_table .
|
was_added
|
true if the query result has been put into
the cache, otherwise
false .
|
was_already_in_cache
|
true if the query result would have been
added to the cache if it was not already in the cache (cache hit).
Otherwise
false .
|
Beispiel #1 mysqlnd_qc_get_query_trace_log() example
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());
?>
Die obigen Bespiele erzeugen folgende Ausgabe:
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) } }