Invalidating query cache entries christian courtship dating rules
First, read the manual, it's written at a very easy-to-understand level.Second, the query cache can be operated in 3 modes only: on, off, and on-demand.I ran SHOW STATUS LIKE "Qcache%" and the results were: Qcache_free_blocks 6941 Qcache_free_memory 23490288 Qcache_hits 253269763 Qcache_inserts 368937684 Qcache_lowmem_prunes 57410566 Qcache_not_cached 9872266 Qcache_queries_in_cache 35275 Qcache_total_blocks 84877 I don't really know what those things mean or if they are even useful in determining whether or not I need to reset the cache. The manual didn't lie to you, any queries which alter data in a table invalidate any cache entries that reference that table. If your data is updated so often that queries would never last in the cache, or the same query is run so infrequently that it's not useful to cache it, then you're just wasting huge amounts of memory and CPU time checking and invalidating cache entries on every Is there a way to turn off the query cache just for selected tables?
That is, even if the query cache is not enabled, the mutex (slow, by nature) to access the (not existing) query cache is acquired for every binlog event.but really, this looks mostly like a case of the actual thread status being misreported, and your issue is insufficient disk I/O bandwidth for the workload (or excessive flushing).