On Fri, 31 Mar 2006 10:34:58 -0500 Sean Davis <[EMAIL PROTECTED]> wrote:
> > > > On 3/31/06 10:01 AM, "Frank Wiles" <[EMAIL PROTECTED]> wrote: > > > On Fri, 31 Mar 2006 14:47:37 +0200 > > Issac Goldstand <[EMAIL PROTECTED]> wrote: > > > >> Granted, I use a few MySQL features for this; I'm not sure if LIMIT > >> exists in postgresql, and I'm fairly sure that the > >> SQL_CALC_FOUND_ROWS directive (which will return the total rows in > >> a select statement regardless of the LIMIT directives) doesn't... > > > > PostgreSQL has LIMIT... it's a SQL standard. And I don't really > > see why you would need SQL_CALC_FOUND_ROWS unless you where going to > > show the total number of pages. For simple Next/Previous paging > > you just keep going until you fall off the end. > > > > If you need to get a count you can just do a count() on a > > particular column without the LIMIT and get a total. > > In postgres, a count(*) can be fairly time-consuming, so a > quick-and-dirty hack is to parse the output of the "EXPLAIN ..." > query to get the estimated number of rows, which is often just fine > as an estimate. If the database is vacuumed often or is basically > query-only, these numbers will often be very close or the same as the > real thing. Right count(*) is very slow in PostgreSQL, but there is plans to improve it in the next release. A much faster way is to do the count on a particular column such as count(id). --------------------------------- Frank Wiles <[EMAIL PROTECTED]> http://www.wiles.org ---------------------------------
