mysqlnd_qc_get_normalized_query_trace_log

(PECL mysqlnd_qc >= 1.0.0)

mysqlnd_qc_get_normalized_query_trace_log — Returns a normalized query trace log for each query inspected by the query cache

说明

mysqlnd_qc_get_normalized_query_trace_log ( void ) : array

Returns a normalized query trace log for each query inspected by the query cache. The collection of the trace log is disabled by default. To collect the trace log you have to set the PHP configuration directive mysqlnd_qc.collect_normalized_query_trace to 1

Entries in the trace log are grouped by the normalized query statement. The normalized query statement is the query statement with all statement parameter values being replaced with a question mark. For example, the two statements SELECT id FROM test WHERE id = 1 and SELECT id FROM test WHERE id = 2 are normalized as SELECT id FROM test WHERE id = ?. Whenever a statement is inspected by the query cache which matches the normalized statement pattern, its statistics are grouped by the normalized statement string.

参数

此函数没有参数。

返回值

An array of query log. Every list entry contains the normalized query stringand further detail information.

Key Description
query Normalized statement string.
occurences How many statements have matched the normalized statement string in addition to the one which has created the log entry. The value is zero if a statement has been normalized, its normalized representation has been added to the log but no further queries inspected by PECL/mysqlnd_qc have the same normalized statement string.
eligible_for_caching Whether the statement could be cached. An statement eligible for caching has not necessarily been cached. It not possible to tell for sure if or how many cached statement have contributed to the aggregated normalized statement log entry. However, comparing the minimum and average run time one can make an educated guess.
avg_run_time The average run time of all queries contributing to the query log entry. The run time is the time between sending the query statement to MySQL and receiving an answer from MySQL.
avg_store_time The average store time of all queries contributing to the query log entry. The store time is the time needed to fetch a statements result set from the server to the client and, storing it on the client.
min_run_time The minimum run time of all queries contributing to the query log entry.
min_store_time The minimum store time of all queries contributing to the query log entry.
max_run_time The maximum run time of all queries contributing to the query log entry.
max_store_time The maximum store time of all queries contributing to the query log entry.

范例

Example #1 mysqlnd_qc_get_normalized_query_trace_log() example

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());
?>

以上例程会输出：

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)
  }
}
相关文章
php ibm db2 函数 returns the auto generated id of the last insert query that successfully executed on this connectionphp maxdb 函数 returns the number of columns for the most recent queryphp maxdb 函数 returns rpl query typephp maxdb 函数 returns the number of warnings from the last query for the given linkphp mssql 函数 returns the number of records affected by the queryphp mysqlnd memcache 函数 returns information about the plugin configurationphp mysqlnd ms 函数 returns a list of currently configured serversphp mysqlnd ms 函数 returns query distribution and connection statisticsphp mysqlnd qc 函数 flush all cache contentsphp mysqlnd qc 函数 returns a list of available storage handlerphp mysqlnd qc 函数 returns information on the current handler the number of cache entries and cache entries if availablephp mysqlnd qc 函数 statistics collected by the core of the query cachephp mysqlnd qc 函数 returns a normalized query trace log for each query inspected by the query cachephp mysqlnd qc 函数 returns a backtrace for each query inspected by the query cachephp sqlite 函数 execute a query against a given database and returns an arrayphp sqlite 函数 executes a query against a given database and returns a result handlephp sqlite 函数 executes a query and returns either an array for one single column or the value of the first rowphp sqlsrv 函数 returns the number of rows modified by the last insert update or delete query executedphp mysqlnd qc mysqlnd qc 函数php sdo das relational 函数 executes a given sql query against a relational database and returns the results as a normalised data graph
关注编程学问公众号