MySQL query cache is good to cache select queries and their results and improve some performance of your database applications. So I thought I should write a quick tutorial to quickly set up the query cache without going into the details. So here what you have to do to enable query cache on MySQL.
If you want to enable query cache without restarting the MySQL server then just run the following command on MySQL prompt/client:
set global query_cache_size=67108864;
This will set MySQL query cache size to around 64MB and also enable the query cache. You can set it to any value you desire. You can then check the status later by running following commands on MySQL prompt/client:
SHOW VARIABLES LIKE ‘%query_cache%’;
SHOW STATUS LIKE ‘%qcache%’;
These commands will show some useful information about the query cache like if query cache is enabled, how much memory is being used, how many queries are currently in cache, cache hit rate etc.
This is really a quick way to enable query cache. For details see MySQL documentation http://dev.mysql.com/tech-resources/articles/mysql-query-cache.html