From: Karsten H. <Kar...@gm...> - 2005-05-17 19:20:22
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On Tue, May 17, 2005 at 09:01:14AM +1000, Timothy Smith wrote: > > is it possible to mke a progress bar for queries? say i have a query > that will take 20 seconds, i'd like to give some feed back to users on > how long this will take. It is sure possible but it is not very useful because - you will need the number of rows in the result - which could be gotten by "select count(*) from ... where ..." - which, however, takes pretty much the same time as the query itself - which is in part due to PostgreSQL's MVCC nature - which cannot be sped up by using an index - because current tuple visibility is not stored in the index - and doing so would create overhead for insert/update Karsten -- GPG key ID E4071346 @ wwwkeys.pgp.net E167 67FD A291 2BEA 73BD 4537 78B9 A9F9 E407 1346 |