Should I sacrifice my innodb_buufer_pool _size/RAM to make space for query_cache_size ?

Question

I have a 16GB dedicated Mysql server database.My innodb_buffer_pool_size is set to around 11GB ,i am implementing query cache in my system ,which has a size of 80mb. From where

Answer 1

NO. The Query cache runs out of steam after perhaps 80MB -- it spends more an more time pruning entries.

I would suggest that over 90% of production systems do (or should) turn off the QC completely.

Keep in mind that every write to a table purges all entries in the QC for that table.

11G on a 16GB dedicated server is a good number for innodb_buffer_pool_size.