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Home -> Community -> Mailing Lists -> Oracle-L -> Re: NOT IN performance problem
Move to EXISTS like this:
SELECT pn.personid
FROM phonenumber pn
WHERE NOT EXISTS (
SELECT NULL
FROM person p
WHERE p.personid=pn.personid);
-- hth Alexandre ----- Original Message ----- To: "Multiple recipients of list ORACLE-L" <ORACLE-L_at_fatcity.com> Sent: Tuesday, June 25, 2002 3:08 PMReceived on Tue Jun 25 2002 - 09:48:24 CDT
>
>
> Hello,
>
> I have encountered a performance problem. I use "Oracle8 Enterprise
Edition
> Release 8.0.5.0.0 - Production."
>
> I have two tables. "phonenumber" and "person", each person has none, one
or
> many phonenumbers referenced to him.
>
> The phonenumber-table is structured like:
> phonenumber.personid
> phonenumber.phonenumber
>
> The person-table is structured like:
> person.personid
> person.name
> person.address
>
>
> I wan't to know which persons that does NOT have any phonenumber(s).
>
> I can write the query as:
> SELECT personid FROM phonenumber WHERE personid NOT IN (
> SELECT personid FROM person);
>
> However, since my tables are quite large, it takes forever to run my
query.
> In the real database both (or
> atleast one) of "person" or "phonenumber" are views.
>
> To figure out who _does_ have phonenumbers is SIGNIFICANTLY faster.
> (SELECT DISTINCT person.personid FROM person, phonenumber WHERE
> person.personid=phonenumber.personid)
>
> I'm wondering how I could restructure or rewrite my query ("who doesn't
have
> any phoinenumbers?") to run faster,
> or if there is anything else I can do to optimize the query?
>
> Any suggestions?
>
>
> --
> /Nils Höglund, Naqua KB
>
> E-mail: nils_at_naqua.se
> Web: http://www.naqua.se/
> Home Phone: +46 (0)18 30 09 19
> Cellular Phone: +46 (0)736 51 74 58
> Address: Nya Valsätrav. 26 B
> SE-756 46
> Uppsala, Sweden
> --
> Please see the official ORACLE-L FAQ: http://www.orafaq.com
> --
> Author: =?iso-8859-1?Q?Nils_H=F6glund?=
> INET: nils_at_naqua.se
>
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-- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Alexandre Gorbatchev INET: alexandre.gorbatchev_at_avermann.de Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
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