RE: SQL statement performance
Hi Guang, Try something like this: select distinct(spid) spid,name,commonname from ( select distinct(spid) spid,name,commonname from results a , species where a.queryspid = species.id union all select distinct(spid) spid,name,commonname from results b , species where a.subjspid = species.id ); HTH, Remco -Oorspronkelijk bericht- Van: Guang Mei [mailto:[EMAIL PROTECTED]] Verzonden: dinsdag 15 mei 2001 1:20 Aan: Multiple recipients of list ORACLE-L Onderwerp: SQL statement performance Oracle : 8.0.5 Platform : Sun SQL statement: select distinct(spid) spid, name, commonname from ( select distinct queryspid spid from results union select distinct subjspid spid from results ) a, species where a.spid=species.id ; Table Species only has 33 records, while table results has about 800 records. There are indexes on queryspid and subjspid. This query is somehow slow. Is there any easy way to speed it up? Thanks. _ Get your FREE download of MSN Explorer at http://explorer.msn.com -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Guang Mei 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: Daemen, Remco 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).
RE: SQL statement performance
Here's another version of the query that has only 1 sort. SELECT a.spid, s.name, s.commonname FROM (SELECT /+* NO_MERGE(b) */ DISTINCT spid FROM (SELECT r.queryspid AS spid FROM results r ,species s WHERE r.subjspid = s.id UNION ALL SELECT r.subjspid FROM results r ,species s WHERE r.subjspid != r.queryspid ANDr.subjspid = s.id) b ) a ,specias s WHERE a.spid = s.id; Kevin -Original Message- Sent: Tuesday, May 15, 2001 6:31 AM To: Multiple recipients of list ORACLE-L Hi Guang, Try something like this: select distinct(spid) spid,name,commonname from ( select distinct(spid) spid,name,commonname from results a , species where a.queryspid = species.id union all select distinct(spid) spid,name,commonname from results b , species where a.subjspid = species.id ); HTH, Remco -Oorspronkelijk bericht- Van: Guang Mei [mailto:[EMAIL PROTECTED]] Verzonden: dinsdag 15 mei 2001 1:20 Aan: Multiple recipients of list ORACLE-L Onderwerp: SQL statement performance Oracle : 8.0.5 Platform : Sun SQL statement: select distinct(spid) spid, name, commonname from ( select distinct queryspid spid from results union select distinct subjspid spid from results ) a, species where a.spid=species.id ; Table Species only has 33 records, while table results has about 800 records. There are indexes on queryspid and subjspid. This query is somehow slow. Is there any easy way to speed it up? Thanks. _ Get your FREE download of MSN Explorer at http://explorer.msn.com -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Guang Mei 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: Daemen, Remco 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: Toepke, Kevin M 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).
SQL statement performance
Oracle : 8.0.5 Platform : Sun SQL statement: select distinct(spid) spid, name, commonname from ( select distinct queryspid spid from results union select distinct subjspid spid from results ) a, species where a.spid=species.id ; Table Species only has 33 records, while table results has about 800 records. There are indexes on queryspid and subjspid. This query is somehow slow. Is there any easy way to speed it up? Thanks. _ Get your FREE download of MSN Explorer at http://explorer.msn.com -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Guang Mei 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).
