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" <[EMAIL PROTECTED]> Sent: Tuesday, June 25, 2002 3:08 PM > > > 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: [EMAIL PROTECTED] > 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: [EMAIL PROTECTED] > > 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: [EMAIL PROTECTED] (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). > -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Alexandre Gorbatchev INET: [EMAIL PROTECTED] 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: [EMAIL PROTECTED] (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).