RE: Oracle Expert and FK indexes
I didn't do what the Oracle Expert told me to do... no time to experiment. I will ask Oracle Support what is going on, thanks for reminding me. Regards, Patrice Boivin Systems Analyst (Oracle Certified DBA) -Original Message- From: Shreter, Hilary [SMTP:[EMAIL PROTECTED]] Sent: Monday, December 17, 2001 4:10 PM To: Multiple recipients of list ORACLE-L Subject:RE: Oracle Expert and FK indexes Hello, Patrice -- I realize that you wrote this last month. Did you ever draw any conclusions about this behavior? I am trodding the foreign key ground right now hoping to find the golden key to a huge performance issue. I found many unindexed foreign keys (using the scripts per Note:16428.1), however none were in the areas I was researching. I wonder if Expert wanted you to drop them if your table has few rows or if it has very little variability in the values. Did you ever find the answer to why Expert suggested this? Just wondering. -Original Message- Sent: Thursday, November 15, 2001 10:30 AM To: Multiple recipients of list ORACLE-L Does someone know why the Oracle Expert would recommend dropping indexes on FK columns? Maybe it calculates there is a low likelihood of the table being locked during referential integrity checks ? I thought it was a good idea to have indexes on FK columns... this is an old 7.3.4.5. database. Regards, Patrice Boivin Systems Analyst (Oracle Certified DBA) -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Boivin, Patrice J 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: Shreter, Hilary 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: Boivin, Patrice J 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: Oracle Expert and FK indexes
Hello, Patrice -- I realize that you wrote this last month. Did you ever draw any conclusions about this behavior? I am trodding the foreign key ground right now hoping to find the golden key to a huge performance issue. I found many unindexed foreign keys (using the scripts per Note:16428.1), however none were in the areas I was researching. I wonder if Expert wanted you to drop them if your table has few rows or if it has very little variability in the values. Did you ever find the answer to why Expert suggested this? Just wondering. -Original Message- Sent: Thursday, November 15, 2001 10:30 AM To: Multiple recipients of list ORACLE-L Does someone know why the Oracle Expert would recommend dropping indexes on FK columns? Maybe it calculates there is a low likelihood of the table being locked during referential integrity checks ? I thought it was a good idea to have indexes on FK columns... this is an old 7.3.4.5. database. Regards, Patrice Boivin Systems Analyst (Oracle Certified DBA) -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Boivin, Patrice J 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: Shreter, Hilary 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: Oracle Expert and FK indexes
If you are not making changes to the parent in the relationship, then the indexes are not needed (at least for locking concerns). hth connor --- Boivin, Patrice J [EMAIL PROTECTED] wrote: Does someone know why the Oracle Expert would recommend dropping indexes on FK columns? Maybe it calculates there is a low likelihood of the table being locked during referential integrity checks ? I thought it was a good idea to have indexes on FK columns... this is an old 7.3.4.5. database. Regards, Patrice Boivin Systems Analyst (Oracle Certified DBA) -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Boivin, Patrice J 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). = Connor McDonald http://www.oracledba.co.uk (mirrored at http://www.oradba.freeserve.co.uk) Some days you're the pigeon, some days you're the statue __ Do You Yahoo!? Everything you'll ever need on one web page from News and Sport to Email and Music Charts http://uk.my.yahoo.com -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: =?iso-8859-1?q?Connor=20McDonald?= 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).
