tuning mysql query cache

The information provided by the Qcache_lowmem_prunes status variable can help you tune the query cache size. It counts the number of queries that have been removed from the cache to free up memory for caching new queries. The query cache uses a least recently used (LRU) strategy to decide which queries to remove from the cache.

FLUSH QUERY CACHE does not remove any queries from the cache, unlike FLUSH TABLES or RESET QUERY CACHE.

SET GLOBAL query_cache_size =
SHOW VARIABLES LIKE 'query_cache_size';

установка значения:

Command-Line Format --query_cache_size=#
Option-File Format query_cache_size
Option Sets Variable Yes, query_cache_size