> -----Original Message----- > From: pginfo [mailto:[EMAIL PROTECTED]] > Sent: Saturday, February 01, 2003 3:50 PM > To: Bruno Wolff III > Cc: [EMAIL PROTECTED] > Subject: Re: [SQL] update and IN vs. EXISTS > > > > > Bruno Wolff III wrote: > > > On Sat, Feb 01, 2003 at 12:40:00 +0100, > > pginfo <[EMAIL PROTECTED]> wrote: > > > > > > If I try to execute: > > > update Table1 set fieldForUpdate = 1 where ID IN > (select T2.ID from > > > Table2); > > > it is running very slow. > > > > You might try: > > update Table1 set fieldForUpdate = 1 from Table2 where > Table1.id = Table2.id; > > > > It is great.It takes 122 sec. > With IN it takes 8000 sec. > > > This uses a nonstandard postgres extension and may not be > portable, if that > > is a concern. > > > > How to resolve the problem with the standart?regards, > iavn. >
This should work as well: update Table1 set fieldForUpdate = 1 where EXISTS (select 1 from Table2 where Table1.IDS=Table2.IDS ); Tambet ---------------------------(end of broadcast)--------------------------- TIP 2: you can get off all lists at once with the unregister command (send "unregister YourEmailAddressHere" to [EMAIL PROTECTED])