以下的文章主要介绍的是mysql 查询缓存的实际应用代码以及查看mysql 查询缓存的大小 ，碎片整理，清除缓存以及监视mysql 查询缓存性能的相关内容的描述，以下就是具体内容的描述，希望在你今后的学习中会有所帮助。
mysql> select @@query_cache_type; +--------------------+ | @@query_cache_type | +--------------------+ | on | +--------------------+ mysql> set query_cache_type=off; mysql> set query_cache_type=on; mysql> mysql> select sql_cache id, title, body from article; mysql> select sql_no_cache id, title, body from article; mysql> show variables like 'have_query_cache'; +------------------+-------+ | variable_name | value | +------------------+-------+ | have_query_cache | yes | +------------------+-------+ 1 row in set (0.00 sec)
查看mysql 查询缓存的大小
mysql> select @@global.query_cache_size; +---------------------------+ | @@global.query_cache_size | +---------------------------+ | 16777216 | +---------------------------+ 1 row in set (0.00 sec) mysql> select @@query_cache_size; +--------------------+ | @@query_cache_size | +--------------------+ | 16777216 | +--------------------+ 1 row in set (0.00 sec)
查看最大缓存结果，如果结果集大于该数，不缓存。
mysql> select @@global.query_cache_limit; +----------------------------+ | @@global.query_cache_limit | +----------------------------+ | 1048576 | +----------------------------+ 1 row in set (0.00 sec)
碎片整理
mysql> flush query cache -> ; query ok, 0 rows affected (0.00 sec)
清除缓存
mysql> reset query cache -> ; query ok, 0 rows affected (0.00 sec)
监视mysql 查询缓存性能：
mysql> flush tables; query ok, 0 rows affected (0.04 sec) mysql> show status like 'qcache%'; +-------------------------+----------+ | variable_name | value | +-------------------------+----------+ | qcache_free_blocks | 1 | | qcache_free_memory | 16768408 | | qcache_hits | 6 | | qcache_inserts | 36 | | qcache_lowmem_prunes | 0 | | qcache_not_cached | 86 | | qcache_queries_in_cache | 0 | | qcache_total_blocks | 1 | +-------------------------+----------+ 8 rows in set (0.06 sec)
看看当前缓存中有多少条信息：
mysql> show status like 'qcache_q%'; +-------------------------+-------+ | variable_name | value | +-------------------------+-------+ | qcache_queries_in_cache | 0 | +-------------------------+-------+ 1 row in set (0.00 sec) mysql> select sql_cache id, title, body from article; mysql> show status like 'qcache_q%'; +-------------------------+-------+ | variable_name | value | +-------------------------+-------+ | qcache_queries_in_cache | 1 | +-------------------------+-------+ 1 row in set (0.00 sec) mysql> show status like 'qcache_f%'; +--------------------+----------+ | variable_name | value | +--------------------+----------+ | qcache_free_blocks | 1 | | qcache_free_memory | 16766728 | +--------------------+----------+ 2 rows in set (0.00 sec)
以上的相关内容就是对mysql 查询缓存的介绍，望你能有所收获。