2011/5/17 Craig Ringer <craig@xxxxxxxxxxxxxxxxxxxxx>: > On 05/17/2011 01:38 PM, Satoshi Nagayasu wrote: >> >> Hi, >> >> 2011/05/17 14:31, Adarsh Sharma wrote: >>> >>> Rick Genter wrote: >>>> >>>> On May 16, 2011, at 10:09 PM, Adarsh Sharma wrote: >>>> >>>> >>>>> Dear all, >>>>> >>>>> I need to research on Memcache in the next few days. >>>>> >>>>> What I want to know is it worth to have memcahed enable in our >>>>> Mysql/ Postgres Production Servers. >>>>> We have databases from 20 to 230 GB and it's not the OLTP just a >>>>> simple OLAP where data is fetched and stored in some meaningful format. >>>>> >>>>> >>>>> What are benefits& why we used memcahed? >>>>> >>>>> What are the bottlenecks to meet? >>>>> >>>> >>>> You need to read about memcached. Memcached is not something you >>>> "enable". You have to program to it. >>>> >>> >>> Thanks Rick, just one question.. >>> >>> At what stage we need memcached & what is the purpose of using it. >>> >>> I just want to know whether it is worth to use memcahced or not as per >>> our requirements. >> >> I just built a software to enable query caching for PostgreSQL >> with using memcached, which adds a proxy layer. >> >> http://pgsnaga.blogspot.com/2011/03/postgresql-query-cache-pqc.html > > Much like with memcached, it looks like you still have to handle your own > cache invalidation with your cache daemon, and it can return outdated or > inconsistent results. Your examples clearly show that. It'd be nice if the > google code front page clearly pointed out that it's not a fully transparent > cache in that it can return stale or inconsistent data and the app has to be > aware of that. > > How do you handle statements that rely on current_timestamp, random(), etc? > What about if their reliance is via a function? Is that just an understood > limitation of the cache, that it'll cache even queries that don't really > make sense to cache? there is also pgmemcache http://pgfoundry.org/projects/pgmemcache/ It is not a proxy but an extension to access memcache from within postgresql. You can use it to build your own querycache. > > -- > Craig Ringer > > -- > Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-general > -- Cédric Villemain 2ndQuadrant http://2ndQuadrant.fr/ ; PostgreSQL : Expertise, Formation et Support -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
