so there are benefits of splitting indexes and tables on different mount points in an instance used for batch loads? such as a data publication model where you ingest deltas?
any data on this? > > From: DENNIS WILLIAMS <[EMAIL PROTECTED]> > Date: 2003/07/15 Tue PM 12:04:24 EDT > To: Multiple recipients of list ORACLE-L <[EMAIL PROTECTED]> > Subject: RE: RE: should you separate indexes from tables in separate dataf > > R, > My personal theory on where this started was benchmarking. Before the > Oracle Wait Interface was developed, about the only hard-core information > you could get on tuning came as a result of people running benchmarks. If > you benchmark a batch program by itself that uses an index to access a > table, you will get much better performance if you place the index and table > on separate devices. > Now, as has been pointed out, in a busy multi-user system with many > users, many tables and indexes, you shouldn't just put the indexes on > separate devices and call it Miller time. You should observe the actual > usage at a time when performance is critical (Cary Millsap does a nice job > of describing this, although he focuses on finding critical applications), > look for devices that are most heavily used, and move data files accordingly > to spread the load. If you sill feel you must keep the table and indexes > separate, you can criss-cross, i.e. put table A on device A and index A on > device B, then table B on device B and index B on device A. > > Dennis Williams > DBA, 80%OCP, 100% DBA > Lifetouch, Inc. > [EMAIL PROTECTED] > > > Dennis Williams > DBA, 80%OCP, 100% DBA > Lifetouch, Inc. > [EMAIL PROTECTED] > > > -----Original Message----- > Sent: Tuesday, July 15, 2003 10:29 AM > To: Multiple recipients of list ORACLE-L > datafiles > > > does anyoen disagree? Didnt this get started with the 'DBA Handbook' or was > it a different text? > > > > > From: "Mercadante, Thomas F" <[EMAIL PROTECTED]> > > Date: 2003/07/15 Tue AM 11:10:05 EDT > > To: Multiple recipients of list ORACLE-L <[EMAIL PROTECTED]> > > Subject: RE: should you seperate indexes from tables in seperate datafiles > > > > R, > > > > Some of it depends on the disk storage. I have always followed the > > time-proven method of organizing disks and placing indexes away from the > > tables they belong to. > > > > Our warehouse is using EMC external disk. What the warehouse architect > did > > was to stripe the EMC disks in such a way that all mount points (Sun > system) > > are spread across all the EMC disks. What this does is to spread all > files > > in the database across all the EMC drives. And with 4 Gig of EMC cache > > available, it further disproves the theory that separing indexes from data > > are required. The end result, in my case, is almost like one big RAM disk > - > > where all disk IO is spread across all disk. > > > > If you do not have this arrangement, then I would still try and keep > indexes > > and data away from each other. But let's face it, we *never* have enough > > disk mount points, so we end up merging things together somewhat anyway. > > > > hope this helps. > > > > Tom Mercadante > > Oracle Certified Professional > > > > > > -----Original Message----- > > Sent: Tuesday, July 15, 2003 10:49 AM > > To: Multiple recipients of list ORACLE-L > > > > > > There has been alot of literature stating that you will recieve > performance > > improvements by seperating indexes and tables across multiple I/O points. > > > > Ie... you have a tables tablespace and an index tablespace. If you put > them > > on seperate hard drives, you will have less I/O contention. > > > > Now Im seeing some articles stating that this is not true. That oracle > > actually accesses indexes and tables serially. Now it might be useful > > seperate indexes from tables for maintenance purposes but this wont lower > > I/O contention. > > > > Can anyone chime in on this? Curious to see where the evidence is leading? > > > > > -- > > Please see the official ORACLE-L FAQ: http://www.orafaq.net > > -- > > Author: <[EMAIL PROTECTED] > > INET: [EMAIL PROTECTED] > > > > Fat City Network Services -- 858-538-5051 http://www.fatcity.com > > San Diego, California -- Mailing list and web hosting services > > --------------------------------------------------------------------- > > 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.net > > -- > > Author: Mercadante, Thomas F > > INET: [EMAIL PROTECTED] > > > > Fat City Network Services -- 858-538-5051 http://www.fatcity.com > > San Diego, California -- Mailing list and web hosting services > > --------------------------------------------------------------------- > > 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.net > -- > Author: <[EMAIL PROTECTED] > INET: [EMAIL PROTECTED] > > Fat City Network Services -- 858-538-5051 http://www.fatcity.com > San Diego, California -- Mailing list and web hosting services > --------------------------------------------------------------------- > 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.net > -- > Author: DENNIS WILLIAMS > INET: [EMAIL PROTECTED] > > Fat City Network Services -- 858-538-5051 http://www.fatcity.com > San Diego, California -- Mailing list and web hosting services > --------------------------------------------------------------------- > 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.net -- Author: <[EMAIL PROTECTED] INET: [EMAIL PROTECTED] Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- 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).
