Tomasz Ostrowski wrote:
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.
Well that explains what I've been seeing (autocommit on scan producing behavior
that looks like SERIALIZABLE). Not the behavior I would prefer, but I understand
it now.
Jack
