Re: setFetchSize
От | Dave Cramer |
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Тема | Re: setFetchSize |
Дата | |
Msg-id | CADK3HHLrGmJkdcCcYoHV9BpMSg+jTXJ3X4LtzhvhRzvaedAWtQ@mail.gmail.com обсуждение исходный текст |
Ответ на | Re: setFetchSize (fschmidt <fschmidt@gmail.com>) |
Ответы |
Re: setFetchSize
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Список | pgsql-jdbc |
On Wed, Oct 26, 2011 at 11:48 AM, fschmidt <fschmidt@gmail.com> wrote: > > Dave Cramer-8 wrote: >> >> There is little hope that you will get what you want. I'm not even >> sure I think it's a good idea as cursor with hold consumes resources >> on the server which multiplied by an unknown number of connections >> might end up being significant. >> > And how is it any better to force users to open a new connection to use > setFetchSize? This would use just as much resources if not more, right? It > is just much more inconvenient for programmers, especially in applications > like mine that are designed to use one connection per thread. My understanding is this: Postgresql is an MVCC database and can easily provide you with a snapshot of a resultset inside a transaction. Outside a transaction my bet is that the data has to be copied to a temporary location somewhere, so if this is done over N connections the resources required could be substantial. > > If there is little hope of getting what I want with Postgres, then I will > eventually have to look for an alternative database. Well every database I know of has it's idiosyncrasies, an as I said the JDBC spec makes no guarantees of what setFetchSize should do if anything. Dave Cramer dave.cramer(at)credativ(dot)ca http://www.credativ.ca
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