RE: how to improve sequential scans ?
jack, this is 7.3.2 so...the only way to partition is to manually spliting the table into multiple disks (as mentioned by Bruce) there are four clients running the same sql (with different value in where clause) causing parsing allocation shared mem... 99.9 % of sorts are in mem. i have just finished creating raw partitions.let's see how my tables perform now... > -- > From: Jack C. Applewhite[SMTP:[EMAIL PROTECTED]] > Reply To: [EMAIL PROTECTED] > Sent: Tuesday, July 17, 2001 8:25 PM > To: Multiple recipients of list ORACLE-L > Subject: RE: how to improve sequential scans ? > > Rahul, > > Could this table be partitioned and the partitions spread across multiple > disks? Could the index be partitioned as well? The concept here is, of > course, "divide and conquer". > > Could a column or two (or three) be added to the index to satisfy the > query > without having to hit the table? > > How frequently are these literal queries being issued? Are they shredding > your shared pool and chewing up CPU by making Oracle do extra work in > shared > pool memory management? > > Are there aggregation (vs aggravation ) functions or order bys in the > queries that might be causing sorts to disk? If aggregation, could you > use > materialized views to satisfy the queries? > > ...just a few ideas. > > Jack > > > Jack C. Applewhite > Database Administrator/Developer > OCP Oracle8 DBA > iNetProfit, Inc. > Austin, Texas > www.iNetProfit.com > [EMAIL PROTECTED] > (512)327-9068 > > > -Original Message- > Sent: Tuesday, July 17, 2001 7:36 AM > To: Multiple recipients of list ORACLE-L > > > list (AIX, 7.3.2) > > 5 clients are shooting the same sql to read data from an 18 million rows > table. > each time the sql uses a different literal value in the where clause... no > bind variables. > > I CANNOT TOUCH THE APPLICATION, and have been given the task to > re-configure > the > DB to increase performance. > > i have moved the table and it;s associated index to separate disks. and > iostat show that > only that only those two disks are being read. > > the session wait show that all the times the sessions are waiting on > "db file sequential read" > > the db file being sequentially read in the above sessiion is the TABLE > from > which > all the sid's are reading > > the table is analyzed and the sql's issued use the index. > > how can i further tune this config. ? > > TIA > > Rahul > > PS: my next step is to put the files on raw disks. > > > -- > Please see the official ORACLE-L FAQ: http://www.orafaq.com > -- > Author: Jack C. Applewhite > 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: Rahul 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: how to improve sequential scans ?
A correction to a typo in the original email What about using outlines to change the SQL execution plan - you could do this without touching the application sql. For an example see http://www.oracledba.co.uk/tips/outlines.htm Regards, Bruce Reardon -Original Message- Sent: Wednesday, 18 July 2001 9:41 Rahul, Some various thoughts: What about splitting the tablespace that the table is in across multiple datafiles and provided the table is in multiple extents it then should split across multiple disks - there are some articles on Ixora referring to this. Kind of a poor-persons partitioning if you don't own a partitioning license. Regards, Bruce Reardon -Original Message- Sent: Tuesday, 17 July 2001 11:26 Rahul, Could this table be partitioned and the partitions spread across multiple disks? Could the index be partitioned as well? The concept here is, of course, "divide and conquer". Could a column or two (or three) be added to the index to satisfy the query without having to hit the table? How frequently are these literal queries being issued? Are they shredding your shared pool and chewing up CPU by making Oracle do extra work in shared pool memory management? Are there aggregation (vs aggravation ) functions or order bys in the queries that might be causing sorts to disk? If aggregation, could you use materialized views to satisfy the queries? .just a few ideas. Jack Jack C. Applewhite Database Administrator/Developer OCP Oracle8 DBA iNetProfit, Inc. Austin, Texas www.iNetProfit.com [EMAIL PROTECTED] (512)327-9068 -Original Message- Sent: Tuesday, July 17, 2001 7:36 AM list (AIX, 7.3.2) 5 clients are shooting the same sql to read data from an 18 million rows table. each time the sql uses a different literal value in the where clause... no bind variables. I CANNOT TOUCH THE APPLICATION, and have been given the task to re-configure the DB to increase performance. i have moved the table and it;s associated index to separate disks. and iostat show that only that only those two disks are being read. the session wait show that all the times the sessions are waiting on "db file sequential read" the db file being sequentially read in the above sessiion is the TABLE from which all the sid's are reading the table is analyzed and the sql's issued use the index. how can i further tune this config. ? TIA Rahul PS: my next step is to put the files on raw disks. -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Reardon, Bruce (CALBBAY) 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: how to improve sequential scans ?
Rahul, Some various thoughts: What about using outlines to change the SQL execution plan - you could do this without touching the execution plans. What about splitting the tablespace that the table is in across multiple datafiles and provided the table is in multiple extents it then should split across multiple disks - there are some articles on Ixora referring to this. Kind of a poor-persons partitioning if you don't own a partitioning license. Regards, Bruce Reardon -Original Message- Sent: Tuesday, 17 July 2001 11:26 Rahul, Could this table be partitioned and the partitions spread across multiple disks? Could the index be partitioned as well? The concept here is, of course, "divide and conquer". Could a column or two (or three) be added to the index to satisfy the query without having to hit the table? How frequently are these literal queries being issued? Are they shredding your shared pool and chewing up CPU by making Oracle do extra work in shared pool memory management? Are there aggregation (vs aggravation ) functions or order bys in the queries that might be causing sorts to disk? If aggregation, could you use materialized views to satisfy the queries? just a few ideas. Jack Jack C. Applewhite Database Administrator/Developer OCP Oracle8 DBA iNetProfit, Inc. Austin, Texas www.iNetProfit.com [EMAIL PROTECTED] (512)327-9068 -Original Message- Sent: Tuesday, July 17, 2001 7:36 AM list (AIX, 7.3.2) 5 clients are shooting the same sql to read data from an 18 million rows table. each time the sql uses a different literal value in the where clause... no bind variables. I CANNOT TOUCH THE APPLICATION, and have been given the task to re-configure the DB to increase performance. i have moved the table and it;s associated index to separate disks. and iostat show that only that only those two disks are being read. the session wait show that all the times the sessions are waiting on "db file sequential read" the db file being sequentially read in the above sessiion is the TABLE from which all the sid's are reading the table is analyzed and the sql's issued use the index. how can i further tune this config. ? TIA Rahul PS: my next step is to put the files on raw disks. -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Reardon, Bruce (CALBBAY) 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: how to improve sequential scans ?
Rahul, Could this table be partitioned and the partitions spread across multiple disks? Could the index be partitioned as well? The concept here is, of course, "divide and conquer". Could a column or two (or three) be added to the index to satisfy the query without having to hit the table? How frequently are these literal queries being issued? Are they shredding your shared pool and chewing up CPU by making Oracle do extra work in shared pool memory management? Are there aggregation (vs aggravation ) functions or order bys in the queries that might be causing sorts to disk? If aggregation, could you use materialized views to satisfy the queries? ...just a few ideas. Jack Jack C. Applewhite Database Administrator/Developer OCP Oracle8 DBA iNetProfit, Inc. Austin, Texas www.iNetProfit.com [EMAIL PROTECTED] (512)327-9068 -Original Message- Sent: Tuesday, July 17, 2001 7:36 AM To: Multiple recipients of list ORACLE-L list (AIX, 7.3.2) 5 clients are shooting the same sql to read data from an 18 million rows table. each time the sql uses a different literal value in the where clause... no bind variables. I CANNOT TOUCH THE APPLICATION, and have been given the task to re-configure the DB to increase performance. i have moved the table and it;s associated index to separate disks. and iostat show that only that only those two disks are being read. the session wait show that all the times the sessions are waiting on "db file sequential read" the db file being sequentially read in the above sessiion is the TABLE from which all the sid's are reading the table is analyzed and the sql's issued use the index. how can i further tune this config. ? TIA Rahul PS: my next step is to put the files on raw disks. -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Jack C. Applewhite 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).
how to improve sequential scans ?
list (AIX, 7.3.2) 5 clients are shooting the same sql to read data from an 18 million rows table. each time the sql uses a different literal value in the where clause... no bind variables. I CANNOT TOUCH THE APPLICATION, and have been given the task to re-configure the DB to increase performance. i have moved the table and it;s associated index to separate disks. and iostat show that only that only those two disks are being read. the session wait show that all the times the sessions are waiting on "db file sequential read" the db file being sequentially read in the above sessiion is the TABLE from which all the sid's are reading the table is analyzed and the sql's issued use the index. how can i further tune this config. ? TIA Rahul PS: my next step is to put the files on raw disks. -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Rahul 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).
