Jan Wieck wrote: > Bruce Momjian wrote: > > > > Wei Weng wrote: > > > Between Using Limit P, S or using a cursor to start from FETCH ABSOLUTE > > > S and FETCH NEXT for P times, which one is faster? > > > > LIMIT is faster because it doesn't need to generate all the result, in > > some cases. > > Neither does using a cursor need to generate all the results first. It's > a portal, which is an executor state on hold, and FETCH is implemented > as ExecutorRun() with the number of wanted result rows as limitation. > Since LIMIT generates internally one more result row than really wanted, > I don't think LIMIT would be much faster, but it's for sure less > portable.
Oh, I thought the portal had to be materialized before returning a row. Thanks. -- Bruce Momjian | http://candle.pha.pa.us [EMAIL PROTECTED] | (610) 853-3000 + If your life is a hard drive, | 830 Blythe Avenue + Christ can be your backup. | Drexel Hill, Pennsylvania 19026 ---------------------------(end of broadcast)--------------------------- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/users-lounge/docs/faq.html
