Re: Subquery
Kevin's right of course, try them all, pick the best performing. Jared On Tuesday 29 May 2001 13:05, Toepke, Kevin M wrote: > Jared, > > At least with O8i, that's true in about 60-70% of the time. I have found it > better to use subqueries instead of joins when that's what you mean. In > some cases the optimizer can eliminate a sort step when using sub-queries > instead of a join and other times it processes less data. > > Sometimes an IN subquery is faster, other times an EXISTS subquery is > faster. The point is, you have to try the query all 3 ways. > > In this case, I suspect that a subquery will be much faster than the join. > (Because of the rownum = 1 restriction) > > Kevin > > -Original Message- > Sent: Tuesday, May 29, 2001 3:11 PM > To: Multiple recipients of list ORACLE-L > > > > Why change it to subqueries? > > The optimizer will just turn it back into a join anyway. > > Jared > > On Tuesday 29 May 2001 05:15, [EMAIL PROTECTED] wrote: > > Hallo you DBAs > > > > How can I write this sql query using subqueries? > > > > SELECT pbk.nielsenart.varunamn, pbk.nielsenart.strl, > > pbk.nielsenart.varutxt, null, pbk.nielsenart.vgrp, > > rik2.hierarki_tekst.tekst, null, pbk.sortiment_vgrp.sortiment, > > pbk.nielsenart.art_grp, pbk.nielsenart.art_ugrp, null FROM > > pbk.nielsenart,pbk.sortiment_vgrp,rik2.hierarki_tekst, pbk.rapporttmp > > WHERE > > > pbk.nielsenart.vgrp=rik2.hierarki_tekst.vgrp > > AND pbk.sortiment_vgrp.vgrp=pbk.nielsenart.vgrp > > AND rik2.hierarki_tekst.sett_id=2 > > AND rik2.hierarki_tekst.landkode=46 > > AND pbk.nielsenart.ean=pbk.rapporttmp.EAN > > AND ROWNUM=1 > > > > > > Roland Sköldblom -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Jared Still 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: Subquery
Jared, At least with O8i, that's true in about 60-70% of the time. I have found it better to use subqueries instead of joins when that's what you mean. In some cases the optimizer can eliminate a sort step when using sub-queries instead of a join and other times it processes less data. Sometimes an IN subquery is faster, other times an EXISTS subquery is faster. The point is, you have to try the query all 3 ways. In this case, I suspect that a subquery will be much faster than the join. (Because of the rownum = 1 restriction) Kevin -Original Message- Sent: Tuesday, May 29, 2001 3:11 PM To: Multiple recipients of list ORACLE-L Why change it to subqueries? The optimizer will just turn it back into a join anyway. Jared On Tuesday 29 May 2001 05:15, [EMAIL PROTECTED] wrote: > Hallo you DBAs > > How can I write this sql query using subqueries? > > SELECT pbk.nielsenart.varunamn, pbk.nielsenart.strl, > pbk.nielsenart.varutxt, null, pbk.nielsenart.vgrp, > rik2.hierarki_tekst.tekst, null, pbk.sortiment_vgrp.sortiment, > pbk.nielsenart.art_grp, pbk.nielsenart.art_ugrp, null FROM > pbk.nielsenart,pbk.sortiment_vgrp,rik2.hierarki_tekst, pbk.rapporttmp WHERE > pbk.nielsenart.vgrp=rik2.hierarki_tekst.vgrp > AND pbk.sortiment_vgrp.vgrp=pbk.nielsenart.vgrp > AND rik2.hierarki_tekst.sett_id=2 > AND rik2.hierarki_tekst.landkode=46 > AND pbk.nielsenart.ean=pbk.rapporttmp.EAN > AND ROWNUM=1 > > > Roland Sköldblom -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Jared Still 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).
Re: Subquery
Why change it to subqueries? The optimizer will just turn it back into a join anyway. Jared On Tuesday 29 May 2001 05:15, [EMAIL PROTECTED] wrote: > Hallo you DBAs > > How can I write this sql query using subqueries? > > SELECT pbk.nielsenart.varunamn, pbk.nielsenart.strl, > pbk.nielsenart.varutxt, null, pbk.nielsenart.vgrp, > rik2.hierarki_tekst.tekst, null, pbk.sortiment_vgrp.sortiment, > pbk.nielsenart.art_grp, pbk.nielsenart.art_ugrp, null FROM > pbk.nielsenart,pbk.sortiment_vgrp,rik2.hierarki_tekst, pbk.rapporttmp WHERE > pbk.nielsenart.vgrp=rik2.hierarki_tekst.vgrp > AND pbk.sortiment_vgrp.vgrp=pbk.nielsenart.vgrp > AND rik2.hierarki_tekst.sett_id=2 > AND rik2.hierarki_tekst.landkode=46 > AND pbk.nielsenart.ean=pbk.rapporttmp.EAN > AND ROWNUM=1 > > > Roland Sköldblom -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Jared Still 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: Subquery
Why would you want to use a subquery? I can see no reason or it and they do tend to slow things down. Dick Goulet -- Reply Separator -- Author: [EMAIL PROTECTED] Date: 5/29/01 4:15 AM Hallo you DBAs How can I write this sql query using subqueries? SELECT pbk.nielsenart.varunamn, pbk.nielsenart.strl, pbk.nielsenart.varutxt, null, pbk.nielsenart.vgrp, rik2.hierarki_tekst.tekst, null, pbk.sortiment_vgrp.sortiment, pbk.nielsenart.art_grp, pbk.nielsenart.art_ugrp, null FROM pbk.nielsenart,pbk.sortiment_vgrp,rik2.hierarki_tekst, pbk.rapporttmp WHERE pbk.nielsenart.vgrp=rik2.hierarki_tekst.vgrp AND pbk.sortiment_vgrp.vgrp=pbk.nielsenart.vgrp AND rik2.hierarki_tekst.sett_id=2 AND rik2.hierarki_tekst.landkode=46 AND pbk.nielsenart.ean=pbk.rapporttmp.EAN AND ROWNUM=1 Roland Sköldblom -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: 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: 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).
