Re: Insert performance

Hi! Search for "surrogate key" in google for example. You have to modify your generated primary key valuesto not hit the same index blocks consecutively. For example, add another high-cardinality column to your primary key, or if using meaningless primary keys then just have your primary

RE: Insert performance

, 2003 11:10 PM To: Multiple recipients of list ORACLE-L Subject: Re: Insert performance At 09:44 PM 9/22/2003, you wrote: Does anyone have any idea how to improve performance for multiple inserts into a table that uses a sequence generated primary key? Is the sequence cache set

RE: Insert performance

, September 23, 2003 4:05 PM To: Multiple recipients of list ORACLE-L Subject: RE: Insert performance I have already bumped that up quite a bit as well, but I still get many waits. Thanks, Rick Stephenson Oracle Database Administrator Ovid Technologies, Inc. [EMAIL PROTECTED

RE: Insert performance

Rick, I haven't tried this myself but you could consider a reverse key index (depending on your version). That way multiple inserts won't go to the same block. However, (from Perf Tuning 101) you will incur much more IO than a normal index if you do range scans, so you'd need to consider how

Re: Insert performance

Re: insert performance

No. CPU utilitization averages 40-60% across 4 CPUs. --- Mohammed Shakir [EMAIL PROTECTED] wrote: No enough inserts to bog down the CPUs? --- Paul Baumgartel [EMAIL PROTECTED] wrote: Thanks, Mohammed and Anjo, for your replies. Now my question is this: given that the table structures

RE: insert performance

Paul - How many insert processes did you run on each system? Is the disk layout identical in terms of spreading across devices? Dennis Williams DBA Lifetouch, Inc. [EMAIL PROTECTED] -Original Message- Sent: Wednesday, April 10, 2002 6:43 PM To: Multiple recipients of list ORACLE-L

RE: insert performance

Dennis-- The faster machine had 10 database connections, the slower, 50. Not all were used in either case. But my comparison is for inserts done by a single session, i.e., it's not the aggregate insert rate, but a direct comparison of the same insert statement in a single session on each

RE: insert performance

Paul - My point is that I have seen performance decrease when too many processes are used. For example, with imports, a multi-cpu system may import faster with two import jobs running. But at some point it seems that Oracle and/or the operating system is just trying to switch between each process

RE: insert performance

Disk layout and disk speed itself matters. While testing one same batch job with similar data on prod and test machine, test machine was performing same job in half of the time(2 hours) than prod(4 hours) and difference was fast fiber optical drives on test box even with slower processor but

Re: insert performance

No enough inserts to bog down the CPUs? --- Paul Baumgartel [EMAIL PROTECTED] wrote: Thanks, Mohammed and Anjo, for your replies. Now my question is this: given that the table structures (freelists, etc.) are identical on the two machines, the init.ora parameters are identical for the two

Re: insert performance

Follow-up question: can someone explain exactly why buffer busy waits can be due to heavy insert activity when there are insufficient freelists? I suspect that this may figure into my problem with insert performance. Thanks! Paul Baumgartel __

Re: insert performance

aul, BBW due to not enough freelists is caused by multiple processes waiting on the head of the freelist to check if there is space in the block. problems can get worse by doing array inserts .. So by having enough freelists, different processes will check on different heads of freelsits.