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From: | Kevin Burton | Date: | June 7 2005 10:36pm |
Subject: | Re: Seriously.. When are we going to get subqueries?! | ||
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DBA wrote: >----- Original Message ----- >From: "Kevin Burton" <burton@stripped> >To: <greg@stripped> >Cc: <mysql@stripped> >Sent: Tuesday, June 07, 2005 6:11 PM >Subject: Re: Seriously.. When are we going to get subqueries?! > > > > >>Greg Whalin wrote: >> >> >> >>>They do use indexes if you use them to build derived tables and are >>>pretty fast. The only case where I see them not using indexes when I >>>think they should is when you use a sub-query for an IN() clause. >>> >>> >>I'm sorry.. yes.. They're not using indexes when within IN clauses which >>for me is 99.9% of the time. >> >>Maybe I'm wrong though and this is a rare but I don't think so... >> >>Kevin >> >> > >I use subqueries and I thought that it was using the index? I might be wrong? This is > MySQL on 4.1.11-nt. Here is the explain plan: > > > Nope... its a bit confusing but no... it's not. The subquery ITSELF is using queries but the parent query which is using your ptt_trans_06 table is not ... Notice the Type: ALL and Key: NULL Luckly though you only have 21k rows so its not that big of a deal. KEvin -- Use Rojo (RSS/Atom aggregator)! - visit http://rojo.com. See irc.freenode.net #rojo if you want to chat. Rojo is Hiring! - http://www.rojonetworks.com/JobsAtRojo.html Kevin A. Burton, Location - San Francisco, CA AIM/YIM - sfburtonator, Web - http://peerfear.org/ GPG fingerprint: 5FB2 F3E2 760E 70A8 6174 D393 E84D 8D04 99F1 4412