Using ASSM in 10g RAC with SAP

[Former Member]

Hi,

It is recommended to use ASSM (Automatic Segment Space Management) with using 10g RAC with SAP. Our deployment is currently a single instance database that is not using ASSM. We plan to convert this single instance database to a 10g RAC database. I wanted to know what the supported method is to convert to ASSM, during this process.

Will it require an export and import of the database?

Thanks

[lbreddemann · Accepted solution]

Hi Badar,

> It is recommended to use ASSM (Automatic Segment Space Management) with using 10g RAC with SAP.

Yes, it is. In fact, ASSM was designed to better support parallel segment access as it's common in RAC setups.

>I wanted to know what the supported method is to convert to ASSM, during this process.

> Will it require an export and import of the database?

The "method" is called reorganisation. You will have to move all segments into new ASSM tablespaces. This can be done online for all tables that don't have any long columns.

For those that still have long (and not lob) columns, an export/import offline reorganisation is necessary.

Both ways of reorganisation are supported by the BRTOOLS.

Hope that answers your questions.

regards,

Lars

[Former Member · Accepted solution]

Thanks lars. Could I use alter table move tablespace to achieve this or does it have to be run through the br tools?

[lbreddemann · Accepted solution]

Hi Badar,

of course you can move tables (w/o longs) via ALTER TABLE MOVE... but why do you may want to do that?

ALTER TABLE MOVE is an OFFLINE action - nobody can access the table during the move.

DBMS_REDEFINITION (used by the BRTOOLS) is ONLINE. Normal work can proceed while the data is copied.

With ALTER TABLE MOVE you've to touch every single table (ca 50.000-80.000 in a SAP installation) by hand. PLUS you've to rebuild each index on each table by hand.

The BRTOOLS do all that for you. In parallel if you want to.

Moreover the BRTOOLS provide extensive logging in case any error should occur. ALTER TABLE MOVE does not.

So better forget about ALTER TABLE MOVE... use the BRTOOLS - they are not that bad

best regards,

Lars

[Former Member · Accepted solution]

Thanks - will read up on the tools - not familiar with them.

[lbreddemann · Accepted solution]

Hi there,

many customers are not familiar yet with the BR*Tools, so you're in good company.

As a starting point you may want to have a look into my blog on the BRTOOLS: [We all hate the BRTOOLS, donu2019t we?|https://www.sdn.sap.com/irj/sdn/weblogs?blog=/pub/wlg/6769] [original link is broken] [original link is broken] [original link is broken];

Best regards,

Lars