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1 JBChakrapani commented Permalink

Thanks for the great information. Am I correct in saying that the muli temperature storage concept is applicable to single partitioned databases and also to range partitioned tables within? How easy/quick is it convert existing tablespaces to use different storage groups - is there a performance impact during the rebalancing?
And if there are issues during the data transfer, does DB2 revert back to the old setting without any problems?
Thanks in advance!

2 JimSeeger commented Permalink


Storage groups are defined at a database level just like a table space. The most common usage scenario will be with range partitioned tables that are partitioned on a date column.
The answer to how easy conversion of existing table spaces and the performance impact on your system depends on the amount of data to be moved. Planning and executing the SQL statements are pretty simple - you can refer to the developer works paper released today for more details.
"Technical paper: DB2 V10.1 Multi-temperature data management recommendations"
REBALANCE moves an extent of data at a time. The SQL statement is logged, but the asynchronous extent movement is not. The table space's extent map is updated after each successful extent movement. Therefore, if some issue does happen and the REBALANCE must be started again, it will pick up from the extent it was last working on. The operation is not reverted.
Hope this helps.
Jim Seeger

3 SergeRielau commented Permalink

Thanks for the comments Jim. Much appreciated.

Does that answer your questions?
I will also update the article with a few more resources.

4 JBChakrapani commented Permalink

Thankyou Jim and Serge. Yes, it answers my questions. I know from my previous experience with rebalancing on V 9.7, there is some performance impact to online applications. But, operations like this are usually done during off peak hours. I am assuming that is true for V10 as well.

5 3434 commented Permalink

Great information, Can I say I could use any storage system to have storage group defined. So once the storage is provisioned on the database server with appropriate disks (SSD, SAS, SATA) create the storage group based on the File systems.

Bobby Oommen

6 SergeRielau commented Permalink


Yes, you can use just about anything.
As part of this blog I even used a thumb-drive.