mysql query cache size

constructs allocated by the serverCmd_get get Command (GET) total number of requestsCmd_set set Command (SAVE) Total Request countGet_hits Total Hit CountTotal number of get_misses missesEvictions the number of items deleted for free memory (the space allocated to memcache needs to be removed when the old items are filled to get space allocated to the new items)Bytes_read Total Bytes read (request bytes)Bytes_written total number of bytes sent (result bytes)Limit_maxbytes The amount of memory a

How to use memory bitsCN.com in mysql cache 2 points firstEnabling cache also brings about overhead, mainly in the following aspects:Before starting the query, you must check the cache.If the query is cached but not in the result set, saving the data after the result is gene

, ensuring consistency in the data (i.e. data consistency in the table and in the buffer).Querying the cache configuration1. See if the query buffer canIn MySQL, you can indicate whether the query cache is available through the Have_query_cache server system variable. Even i

Implementation of php + mysql cache technology. This tutorial is suitable for PHP programmers who are interested in caching SQL queries to reduce the load on database connection and execution and improve script performance. Overview Many websites use databases for readers This tutorial is applicable to PHP programmers who are interested in caching SQL queries to reduce the load on database connection and e

table having only one corresponding global lock, and n configuring whether to enable the MySQL query cache with 2 parameters: Query_cache _type and Query_cache_size, where any one of the parameters is set to 0, means that the query caching feature is turned off, but the correct settings are recommended Query_cache_typ

MySQL Status View qps/tps/cache Hit rate view running MySQL Status View monitor running MySQL, one way is to view MySQL running status. (1) QPS (query amount per second) qps = Questions (or Queries)/secondsmysql > show global st

Reprinted: mysql status view QPSTPS cache hit rate view Reprinted: http://blog.163.com/ji_1006/blog/static/106123412013101421530142/ View the running mysql status Monitor running mysql. one of the following methods is to view the running status of mysql.(1) QPS (queries per

, this part of the free memory is a query 1 after the release of query, assuming that this space large and small in MySQL set the size of the memory block, you can no longer be used, causing debris problems Request allocation memory block at the beginning of the query the a

Suitable for readers This tutorial is suitable for PHP programmers who are interested in caching SQL queries to reduce the load on database connections and execution, and improve script performance.Overview Many sites use databases as containers for site data storage. The database contains production information, directory structure, articles, or message books, some of which are likely to be completely static, and will benefit greatly from a cache sy

MySQL Query optimization lecture administrator's optimization measures the optimization measures described in the previous section are not executed by privileged MySQL users. The system administrator of the MySQL server or computer can perform additional optimization measures. For example, some server parameters are at

Compare the buffer query and no buffer query of MySQL in PHP, phpmysql About cache query and unbuffered QueryThe MySQL client has two types of queries:Buffer query:The query results wil

unique row. 4. In some cases, a group by can be solved BY reading the key in sequence (or sorting on the Key), and then calculating the summary until the key value changes. In this case, LIMIT # does not calculate any unnecessary GROUP. 5. As long as MySQL has sent the first line to the customer, it will discard the query. 6. LIMIT 0 always returns an empty set quickly. This is useful for checking the

From subcategory as C Inner JOIN item as I on i.subcategory = C.id GROUP BY C.id Having count (*) > 2000; --Choose one of the results, then SELECT * FROM subcategory where id =???? --Result:category = 14 I got an appropriate value of 14, which is used in the following query. This is the statement used to query subcategory for all of the item numbers in category 14 greater than 2000:

Mysql cache function analysis: 1. The key Generation Principle of the mysql cache function is to generate a unique key based on the select statement according to certain hash rules. The select result generates a value, that is, key => value.Therefore, for the cache, select s

distribution, which indicates the ratio of the interval. In this example, the number of queries between 1 s and 10 s is twice that of 10 s. Tables: Tables involved in the query Explain: SQL statement # Query 1: 0 QPS, 0x concurrency, ID 0xF9A57DD5A41825CA at byte 802 ______# This item is included in the report because it matches --limit.# Scores: V/M = 0.00# Time range: all events occurred at 2016-11-22 06

actual complete data, but the effect is the same. I want to find all subcategory with more than 2000 items in a category. First, I found a subcategory item with a number greater than 2000 and used its category in the following query. Here are the specific query statements: [SQL] The Code is as follows: Select c. id From subcategory as c Inner join item as I on I. subcategory = c. id Group by c. id Having

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About buffered queries and no buffer queriesThere are two types of queries for MySQL clients:buffered queries: will receive the results of the query and store them in the client's cache, and the request to obtain row records is only obtained locally.(1) Advantage: You can move the "current row" pointer freely in the result set, which is easy to find because the r

specified, MySQL records the binlog of all databases outside the specified database.There is a common concept of "binlog-do-db=db_name" and "Binlog_ignore_db=db_name" two parameters:The db_name in the parameter is not the database in which the value query statement was updated, but the database currently in which query was executed. Regardless of updating the da

restart MySQL: Query_cache_size = 268435456--Sets the amount of memory used by the query cache, which defaults to 0 and the size must be 1024 of the entire number of parts Query_cache_type = 1-Cache all queries Query_cache_limit = 1048576--The maximum capac