mysqlnd_qc_get_query_trace_log
(PECL mysqlnd_qc >= 1.0.0)
mysqlnd_qc_get_query_trace_log — Returns a backtrace for each query inspected by the query cache
説明
array
mysqlnd_qc_get_query_trace_log
( void
)
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.
パラメータ
この関数にはパラメータはありません。
返り値
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.
|
例
例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());
?>
上の例の出力は以下となります。
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)
}
}
参考
- Runtime configuration
- mysqlnd_qc.collect_query_trace
- mysqlnd_qc.query_trace_bt_depth
- mysqlnd_qc.time_statistics
- mysqlnd_qc.cache_no_table
- mysqlnd_qc_get_normalized_query_trace_log() - Returns a normalized query trace log for each query inspected by the query cache
忘却曲線を使ってこの関数を確実に記憶に残す
