8288分类目录 8288分类目录 8288分类目录
  当前位置:海洋目录网 » 站长资讯 » 站长资讯 » 文章详细 订阅RssFeed

PHP - Manual: mysqlnd_qc_get_cache_info

来源:网络转载 浏览:45739次 时间:2024-04-13
mysqlnd_qc_get_core_stats » « mysqlnd_qc_get_available_handlers
  • PHP 手册
  • 函数参考
  • 数据库扩展
  • 针对各数据库系统对应的扩展
  • MySQL
  • mysqlnd_qc
  • mysqlnd_qc 函数

mysqlnd_qc_get_cache_info

(PECL mysqlnd_qc >= 1.0.0)

mysqlnd_qc_get_cache_info — Returns information on the current handler, the number of cache entries and cache entries, if available

说明

mysqlnd_qc_get_cache_info ( void ) : array

参数

此函数没有参数。

返回值

Returns information on the current handler, the number of cache entries and cache entries, if available. If and what data will be returned for the cache entries is subject to the active storage handler. Storage handler are free to return any data. Storage handler are recommended to return at least the data provided by the default handler, if technically possible.

The scope of the information is the PHP process. Depending on the PHP deployment model a process may serve one or more web requests.

Values are aggregated for all cache activities on a per storage handler basis. It is not possible to tell how much queries originating from mysqli, PDO_MySQL or mysql.API calls have contributed to the aggregated data values. Use mysqlnd_qc_get_core_stats() to get timing data aggregated for all storage handlers.

Array of cache information

handler string

The active storage handler.

All storage handler. Since 1.0.0.

handler_version string

The version of the active storage handler.

All storage handler. Since 1.0.0.

num_entries int

The number of cache entries. The value depends on the storage handler in use.

The default, APC and SQLite storage handler provide the actual number of cache entries.

The MEMCACHE storage handler always returns 0. MEMCACHE does not support counting the number of cache entries.

If a user defined handler is used, the number of entries of the data property is reported.

Since 1.0.0.

data array

The version of the active storage handler.

Additional storage handler dependent data on the cache entries. Storage handler are requested to provide similar and comparable information. A user defined storage handler is free to return any data.

Since 1.0.0.

The following information is provided by the default storage handler for the data property.

The data property holds a hash. The hash is indexed by the internal cache entry identifier of the storage handler. The cache entry identifier is human-readable and contains the query string leading to the cache entry. Please, see also the example below. The following data is given for every cache entry.

statistics array

Statistics of the cache entry.

Since 1.0.0.

Property Description Version
rows Number of rows of the cached result set. Since 1.0.0.
stored_size The size of the cached result set in bytes. This is the size of the payload. The value is not suited for calculating the total memory consumption of all cache entries including the administrative overhead of the cache entries. Since 1.0.0.
cache_hits How often the cached entry has been returned. Since 1.0.0.
run_time Run time of the statement to which the cache entry belongs. This is the run time of the uncached statement. It is the time between sending the statement to MySQL receiving a reply from MySQL. Run time saved by using the query cache plugin can be calculated like this: cache_hits * ((run_time - avg_run_time) + (store_time - avg_store_time)). Since 1.0.0.
store_time Store time of the statements result set to which the cache entry belongs. This is the time it took to fetch and store the results of the uncached statement. Since 1.0.0.
min_run_time Minimum run time of the cached statement. How long it took to find the statement in the cache. Since 1.0.0.
min_store_time Minimum store time of the cached statement. The time taken for fetching the cached result set from the storage medium and decoding Since 1.0.0.
avg_run_time Average run time of the cached statement. Since 1.0.0.
avg_store_time Average store time of the cached statement. Since 1.0.0.
max_run_time Average run time of the cached statement. Since 1.0.0.
max_store_time Average store time of the cached statement. Since 1.0.0.
valid_until Timestamp when the cache entry expires. Since 1.1.0.
metadata array

Metadata of the cache entry. This is the metadata provided by MySQL together with the result set of the statement in question. Different versions of the MySQL server may return different metadata. Unlike with some of the PHP MySQL extensions no attempt is made to hide MySQL server version dependencies and version details from the caller. Please, refer to the MySQL C API documentation that belongs to the MySQL server in use for further details.

The metadata list contains one entry for every column.

Since 1.0.0.

Property Description Version
name The field name. Depending on the MySQL version this may be the fields alias name. Since 1.0.0.
org_name The field name. Since 1.0.0.
table The table name. If an alias name was used for the table, this usually holds the alias name. Since 1.0.0.
org_table The table name. Since 1.0.0.
db The database/schema name. Since 1.0.0.
max_length The maximum width of the field. Details may vary by MySQL server version. Since 1.0.0.
length The width of the field. Details may vary by MySQL server version. Since 1.0.0.
type The data type of the field. Details may vary by the MySQL server in use. This is the MySQL C API type constants value. It is recommended to use type constants provided by the mysqli extension to test for its meaning. You should not test for certain type values by comparing with certain numbers. Since 1.0.0.

The APC storage handler returns the same information for the data property but no metadata. The metadata of a cache entry is set to NULL.

The MEMCACHE storage handler does not fill the data property. Statistics are not available on a per cache entry basis with the MEMCACHE storage handler.

A user defined storage handler is free to provide any data.

范例

Example #1 mysqlnd_qc_get_cache_info() example

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());
?>

以上例程会输出:

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)
       }
     }
   }
 }
}

参见

  • mysqlnd_qc_get_core_stats() - Statistics collected by the core of the query cache
add a note

User Contributed Notes

There are no user contributed notes for this page.

官方地址:https://www.php.net/manual/en/function.mysqlnd-qc-get-cache-info.php

  推荐站点

  • At-lib分类目录At-lib分类目录

    At-lib网站分类目录汇集全国所有高质量网站,是中国权威的中文网站分类目录,给站长提供免费网址目录提交收录和推荐最新最全的优秀网站大全是名站导航之家

    www.at-lib.cn
  • 中国链接目录中国链接目录

    中国链接目录简称链接目录,是收录优秀网站和淘宝网店的网站分类目录,为您提供优质的网址导航服务,也是网店进行收录推广,站长免费推广网站、加快百度收录、增加友情链接和网站外链的平台。

    www.cnlink.org
  • 35目录网35目录网

    35目录免费收录各类优秀网站,全力打造互动式网站目录,提供网站分类目录检索,关键字搜索功能。欢迎您向35目录推荐、提交优秀网站。

    www.35mulu.com
  • 就要爱网站目录就要爱网站目录

    就要爱网站目录,按主题和类别列出网站。所有提交的网站都经过人工审查,确保质量和无垃圾邮件的结果。

    www.912219.com
  • 伍佰目录伍佰目录

    伍佰网站目录免费收录各类优秀网站,全力打造互动式网站目录,提供网站分类目录检索,关键字搜索功能。欢迎您向伍佰目录推荐、提交优秀网站。

    www.wbwb.net