Niphlod, Just out of curiosity. Is the dal connection pooled? If in postgres you CLUSTER on the salary index do figures change?
mic 2012/2/10 BrendanC <bren...@gmail.com>: > Niphlod, > Thanks (belatedly) for your valuable contribution and your test results. > The only thing missing from your test is contention for database > resources/connections and that is what prompted my initial question. In the > past I worked on a client server application where we had performance issues > re getting and releasing database connections (this was against a heavily > used clinical trials Oracle database). > > I'm very clear on the value of adding indexes to the database - however that > is a bit tangential to my initial question - which was primarily focused on > understanding the limitations/boundaries of using the DAL and connection > management. > > I'm curious about your statement that the DAL will always use the same > connection. My understanding is that the DAL closes and reopens the database > connection for each request. Whether it's the same connection or not may > not matter - once you close a db connection it goes back into the pool and > you may/may not incur a delay in opening new connection. (In a lightly > loaded system you may never see this issue however). > > I was under the impression that minimizing db connections was desirable to > prevent thrashing. In the real world this may no longer be an issue. I do > however recall this being an issue in the past and it's something that is > seldom mentioned in Web development. > > Finally, just so there is no confusion here - I'm not criticizing web2py or > the DAL here - my question is equally valid for Rails, Django etc - afaik > all these frameworks close and reopen connections for each request. > > Again thanks for your thoughtful response to my initial question. > > BrendanC > >
