On Wed, Sep 17, 2008 at 12:42 PM, Ananda Kumar <[EMAIL PROTECTED]> wrote: >>query_cache_limit is the maximum size of a single resultset in the >> cache. If your query results in a bigger resultset it will never get >> into the cache even if its room for it in the cache itself. > > > > Even if there is room why will it not fit into the cache.
Because the query_cache_limit prevents it. Why you'd want to limit that is another question. It's probably to get a more even distribution of whats in the cache, so not one single query makes mysql flush out the whole rest of the cache. Lets say you make 3 queries, where the second one is a query with a huge resultset. SMALL, HEAVY QUERY HUGE, SIMPLE QUERY SMALL, HEAVY QUERY again (the same as the first one) And the two others are the another query, wich is slow to perform. A query_cache_limit might prevent the first query from beeing flushed, which will make you able to use the cache for the third query. > > On 9/17/08, Bard Aase <[EMAIL PROTECTED]> wrote: >> >> On Wed, Sep 17, 2008 at 11:54 AM, Uwe Kiewel <[EMAIL PROTECTED]> wrote: >> > Bard Aase schrieb: >> >> On Wed, Sep 17, 2008 at 11:37 AM, Uwe Kiewel <[EMAIL PROTECTED]> >> >> wrote: >> >>> Hi, >> >>> >> >>> I have two questions regarding the query cache: >> >>> >> >>> 1. What is the difference between query_cache_limit and >> >>> query_cache_size? >> >> >> >> query_cache_limit is the maximum size of a single resultset in the >> >> cache. If your query results in a bigger resultset it will never get >> >> into the cache even if its room for it in the cache itself. >> >> >> >> query_cache_size is the maximum amount of data that may be stored in >> >> the cache. >> > >> > Do you talk about all usable cache memory for all resultsets? >> >> Yes >> >> >> >> -- >> mvh base (Bård Aase) >> MSN: [EMAIL PROTECTED] >> http://blog.elzapp.com >> :wq >> >> -- >> MySQL General Mailing List >> For list archives: http://lists.mysql.com/mysql >> To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED] >> > > -- mvh base (Bård Aase) MSN: [EMAIL PROTECTED] http://blog.elzapp.com :wq -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
