mysql> show variables like '%query_cache%';
(query_cache_type 为 ON 表示已经开启)
+------------------------------+----------+
| Variable_name | Value |
+------------------------------+----------+
| have_query_cache | YES |
| query_cache_limit | 1048576 |
| query_cache_min_res_unit | 4096 |
| query_cache_size | 20971520 |
| query_cache_type | ON |
| query_cache_wlock_invalidate | OFF |
+------------------------------+----------+
如果不是ON,修改配置文件以开启查询缓存:
> vi /etc/my.cnf
[mysqld]中添加:
query_cache_size = 20M
query_cache_type = ON
重启mysql服务:
> service mysql restart
查看缓存使用情况:
mysql> show status like 'qcache%';
+-------------------------+----------+
| Variable_name | Value |
+-------------------------+----------+
| Qcache_free_blocks | 83 |
| Qcache_free_memory | 19811040 |
| Qcache_hits | 3108196 |
| Qcache_inserts | 757254 |
| Qcache_lowmem_prunes | 20720 |
| Qcache_not_cached | 47219 |
| Qcache_queries_in_cache | 47 |
| Qcache_total_blocks | 276 |
+-------------------------+----------+