scott.marlowe wrote: > On Fri, 5 Sep 2003, CSN wrote: > > > Since you usually need to know the total number of > > rows a query would return, do you think it's better > > to: > > > > a) Do one query with a LIMIT and OFFSET to get the > > results, and another COUNT query to get the total > > number of rows? > > > > b) Do a single query without a LIMIT and OFFSET, then > > do a seek or similiar to get at the rows you want? > > > > Most tutorials, code, etc. I've seen do "a". The > > eclipse library does "b". > > Either way works. Does the eclipse library use a cursor, or grab the > whole dataset and then seek on the client side? If it uses a cursor, I'd > expect it to be the fastest and simplest implementation. Since a lot of > libs are designed to work with MySQL, they often are written in the first > method, where select count(*) is quite quick on MySQL, and MySQL doesn't > have cursor support. > > With Postgresql, the cursor is likely to be the faster method.
I agree --- with a LIMIT and COUNT(*), you run the query twice. With a cursor, you run it once, and only pull the rows to the client you want. -- Bruce Momjian | http://candle.pha.pa.us [EMAIL PROTECTED] | (610) 359-1001 + If your life is a hard drive, | 13 Roberts Road + Christ can be your backup. | Newtown Square, Pennsylvania 19073 ---------------------------(end of broadcast)--------------------------- TIP 7: don't forget to increase your free space map settings
