High Rollback Per Cent in SAP

[Former Member]

I have been reviewing Oracle Statspack reports generated in our SAP R/3 database and one of the statistics that jumped out at me is a very high Rollback per Transaction percent of over 45%. I support other non-SAP Oracle databases and have never seen anything like this. I am somewhat new to SAP and realize this might be normal (??), but this leads me to be concerned about what is happening in the environment. My question is..... Is this normal in an SAP Oracle database and if so why? Or is this truely a problem that needs serious further analysis?

We are running Oracle 9.2.0.5 on a 16-way Sun server. The Oracle load profile looks something like this:

Logical Reads (100,000/s)

Physical Reads (2,100/s)

Physical Writes (550/s)

Transactions (100/s)

RollBack per Transaction % (45%)

[Former Member]

To see rollback segmnet usage, please use the v$rollstat in the st04 --> detailed analisys and then extend the psaproll tablespace if it is necessary. How many rollback segments have you? Normally is sufficient to use 20 rollback segs.

Bye

[former_member204746]

unless you use AUM which, in the SAP world, uses tablepace name PSAPUNDO (compared to UNDOTBS under standard Oracle)...

[Former Member]

We have 130G PSAPUNDO tablespace setup with undo retention set to 12 hours. Any clues on the high transaction rollback rate?

[former_member204746]

You should not run statspack if using SAP.

your statistics should be calculated using:

brconnect -c -u / -f stats

as for 45% rollback, I cannot really answer.

[Former Member]

This is the Oracle "statspack" performance analysis monitoring package not the "runstats" datbase statistics gathering package. Database statistics are run through SAP.