Re: Autocommit, isolation level, and vacuum behavior

On 2008-09-11 18:03, Jack Orenstein wrote:

>> When you do:
>> result = query("select something from sometable")
>> then all rows of a result will be cached by a client program.
>
> I am very sure this is not happening. Maybe some rows are being
> cached (specifying fetch size), but certainly not all of them. It
> used to, with older drivers, (7.4?) but I've been using 8.1 drivers
> (at least) for a long time. Maybe some result set options you're
> using cause such memory usage?

Wanna bet?

http://jdbc.postgresql.org/documentation/83/query.html#query-with-cursor
| There a number of restrictions which will make the driver silently
| fall back to fetching the whole ResultSet at once. (...) The
| Connection must not be in autocommit mode. The backend closes cursors
| at the end of transactions, so in autocommit mode the backend will
| have closed the cursor before anything can be fetched from it.

So, when you turn on autocommit then it is caching it all. Fetch size is
ignored.

Regards
Tometzky
--
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moment just before you began to eat it which was better than when you
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