OLAP Cache setting

[Former Member]

Hi All,

Regarding the OLAP cache, I have a huge list query off an ODS that when run appears within the cache. When I rerun the query, instead of using the results from the cache, it goes against the ODS again.

In looking at the settings on the ODS, I have the following:

- Main memory Cache without swapping

- Query to read when you expand or navigate.

I've checked the settings on the cache and they are as follows:

- It is active

- Persistence mode - Flat File

Any ideas why it's not reading the cache the second time the query is called? Should I perhaps change the second setting in the ODS to a persistent cache. I assume that I would have to then change all existing queries manually.

Thanks,

Robert Zovic

[Former Member]

Are you running the query exactly as it was run the first time - no change in variable values, drilldowns etc?

Some questions about your stmt that says your ODS is set for main memory cache, but then you say the the cache setting is persistent mode - flat file.

Persistent Mode - Flat File indicates the results are stored to a flat file cache rather than main memory. It is possible to have a system wide OLAP cache setting one way, the InfoProvider another, and an individual query set yet another way. Based on your post, are you saying the system setting is Persistent Mode - Flat File, but the Infoprovider cache setting for this ODS is Main Memory?

If that's the case, you might want to check and see how much memory is allocated to the main memory cache. The default value is very small, don't remember for sure, but think it is only 4 mb. It may simply be that your data just won't fit.

[Former Member]

Actually I'm off-site right now so I'll have to wait until Monday. However, I did play around with the persistent mode. When I set it to BLOB it worked. Setting it to the other 3 had no effect which may be because of settings.

The setting was done at the query level in RSRT.

Robert

[Former Member]

Do you have one or multiple Appl Servers? The Persistence Settings can be set to be just for that Appl Server or Cross Appl Server. The BLOB setting is saving the the OLAP data to an Oracle table.

So when you get back check the Global OLAP Cache size. I know there were some OSS notes about cache invalidation, but my recollection was the problem was the other way around, the cache was not getting invalidated when it should have been and the query used the cache when it shouldn't have, but it still might be worth a look.

[Former Member]

I believe that there is a single combination app/db server. Do you know where I can find the setting for the cache? Is it set through RSRCACHE or through the instance profile?

Btw, I know about the setting in the IMG. is this the only one.

Thanks for your help.

Robert

Message was edited by: Robert Zovic

[Former Member]

here you can find what you need about olap cache:

http://help.sap.com/saphelp_bw320/helpdata/en/41/b987eb1443534ba78a793f4beed9d5/frameset.htm

PL