Barry, Is it true ? I create table with one column varchar(500) and enter 1 milion rows with length 10-20 character.JDBC query 'select * from a' get error 'out of memory', but psql not. I insert 8 milion rows and psql work fine yet (slow, but work)
In C library is 'execute query' without fetch - in jdbc execute fetch all rows and this is problem - I think that executequery must prepare query and fetch (ResultSet.next or ...) must fetch only fetchSize rows. I am not sure, but I think that is problem with jdbc, not postgresql Hackers ? Does psql fetch all rows and if not how many ? Can I change fetch size in psql ? CURSOR , FETCH and MOVE isn't solution. If I use jdbc in third-party IDE, I can't force this solution regards On Thursday 10 October 2002 06:40 pm, Barry Lind wrote: > Nick, > > This has been discussed before on this list many times. But the short > answer is that that is how the postgres server handles queries. If you > issue a query the server will return the entire result. (try the same > query in psql and you will have the same problem). To work around this > you can use explicit cursors (see the DECLARE CURSOR, FETCH, and MOVE > sql commands for postgres). > > thanks, > --Barry > > Nick Fankhauser wrote: > > I'm selecting a huge ResultSet from our database- about one million rows, > > with one of the fields being varchar(500). I get an out of memory error > > from java. > > > > If the whole ResultSet gets stashed in memory, this isn't really > > surprising, but I'm wondering why this happens (if it does), rather than > > a subset around the current record being cached and other rows being > > retrieved as needed. > > > > If it turns out that there are good reasons for it to all be in memory, > > then my question is whether there is a better approach that people > > typically use in this situation. For now, I'm simply breaking up the > > select into smaller chunks, but that approach won't be satisfactory in > > the long run. > > > > Thanks > > > > -Nick > > > > ------------------------------------------------------------------------- > >- Nick Fankhauser [EMAIL PROTECTED] Phone 1.765.935.4283 Fax > > 1.765.962.9788 Ray Ontko & Co. Software Consulting Services > > http://www.ontko.com/ > > > > > > ---------------------------(end of broadcast)--------------------------- > > TIP 5: Have you checked our extensive FAQ? > > > > http://www.postgresql.org/users-lounge/docs/faq.html > > ---------------------------(end of broadcast)--------------------------- > TIP 6: Have you searched our list archives? > > http://archives.postgresql.org ---------------------------(end of broadcast)--------------------------- TIP 2: you can get off all lists at once with the unregister command (send "unregister YourEmailAddressHere" to [EMAIL PROTECTED])
