Re: Speedup the dml ??
Date: Fri, 14 Apr 2000 15:58:17 +0200
Message-ID: <8d786a$rj4$1_at_scesie13.sie.siemens.at>
Agi,
what is your proccess time for this statement ?
*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-
Pavel Drs
Key Account Manager
ANF Data
Pujmanove 1221
Praha 4
tel. 02-6449635
pavel.drs_at_anfdata.cz
feib <agi_at_feib.com.tw> píše v diskusním příspěvku:MPG.13617895ac05bf43989683_at_news.gcn.net.tw...
> Hello, there
> I have two tables a,b ( a with 600000 records, b 60000 records)
> Both a and b have the same columns c1 c2 c3 c4 c5.
> I want to update a's c5 by b's c5 for the same key value c1-c4.
> So,I create two unique indexies on a(c1,c2,c3,c4) and b(c1,c2,c3,c4).
>
> update a
> set c5 = ( select c5
> from b
> where a.c1=b.c1
> and a.c2=b.c2
> and a.c3=b.c3
> and a.c4=b.c4 );
>
> Are there any better statement ( like EXISTS,or any hint to speedup)
??
> Any ideas ??
>
> Rgds,
> Agi Chen
>
>
>
>
Received on Fri Apr 14 2000 - 15:58:17 CEST