Hi Devrim, You can use the EXPLAIN ANALYZE syntax to find out quite easily.
Chris ----- Original Message ----- From: "Devrim GUNDUZ" <[EMAIL PROTECTED]> To: "PostgreSQL Mailing Lists-SQL" <[EMAIL PROTECTED]> Sent: Monday, August 19, 2002 7:22 PM Subject: [SQL] performance comparison: DISTINCT and GROUP BY > > Hi, > > We have two different queries: > > SELECT name,surname FROM my_table GROUP BY name; > > and > > SELECT DISTINCT on(name) name,surname * FROM my_table; > > which gives us the same result. > > Do these queries differ by their performances? I mean, which one works > faster? DISTINCT or GROUP BY? > > Best regards. > > -- > > Devrim GUNDUZ > > [EMAIL PROTECTED] Tel : (312) 295 9318 > [EMAIL PROTECTED] Faks : (312) 295 9494 > > Web : http://devrim.oper.metu.edu.tr > ------------------------------------- > > > ---------------------------(end of broadcast)--------------------------- > TIP 2: you can get off all lists at once with the unregister command > (send "unregister YourEmailAddressHere" to [EMAIL PROTECTED]) > ---------------------------(end of broadcast)--------------------------- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/users-lounge/docs/faq.html
