Delete DDLOG table...

[Former Member]

Hi,

This is related to BW3.1C system on Oracle.

Our DDLOG table is large (around 8GB).

We want to truncate this table when we bring the system down next time in a week. Note <b>36283</b> talks about this. Note 830965 also suggests that delete the entries when system is down if table is large.

SAP has also recommended that this table is larger in the Early Watch analysis but did not suggest anything.

Is it OK to delete all the entries from this table?

Please advice me.

I will really appreciate your help.

Thank you everybody for the help.

SC.

[Former Member · Accepted solution]

Hi Sume,

In order to avoid data inconsistencies, changes to the buffered objects are passed to the application servers through buffer synchronization which runs periodically. During this synchronization, the application servers read the changes logged in the central database table DDLOG and update their buffers accordingly. DDLOG occupies a special position because its entries are usually deleted automatically again as part of the buffer synchronization. However, in certain problem situations, it may be that no entries are deleted and the table will continue to increase in size.

So deleting the entries should not be a problem.

In terms of table size you should note that deleting the table records does not influence the physical size of the table. The table shrinks in size only after a reorganization, which frees up the allocated database space. The best way to run a reorg is online (depending on the database system you are using). However, if this is not possible, as a workaround in this case, you can stop all SAP instances and empty DDLOG using "TRUNCATE TABLE DDLOG". Refer to following SAP Notes

• 36283 : Buffer Synchronization

• <b>706478: Preventing size of Basis tables from increasing considerably</b>

• 830965 : VBDATA, DDLOG: Size and Growth

Hope this helps!

Thanks,

Preethika

[Former Member · Accepted solution]

Thank you very much to both of you for assurance.

Thank you.

SC

[Former Member]

Hi Sume,

I agree with Preethika.

The contents of table DDLOG are only critical when keeping the SAP buffers synchronised in all application servers of the running SAP system. If you stop the entire SAP system and remove all entries from DDLOG, when the system restarts, all application servers build their buffers based on the contents of the database tables that make up the various buffers. In other words, at system startup, all buffers are synchronised by the system start process. Table DDLOG only becomes important when data in one of the buffers on an application server is changed and the other application servers need to be notified of the change to a buffered object.

Regards,

Gary