DB2 Image Copy

In a Production environment, there are constant updates happening on your DB2 tables as a result of several jobs/programs functionality. These updates are nothing but the results of the execution of  Insert/Update/Delete statement on your various DB2 tables.

What if, I want to take a look at the data in tables before my today's batch pass ran ?? this may be for some analysis/understanding  or worse inadvertently something went  wrong and you want to recover the data back to where it was before the job ran. Is there a way? Wouldn't it be nice if some one can take a back up of my DB2 tables before the batch pass run so I can always go and get it back where we started.

Well , it's already happening the only thing is as a programmer/ developer you may not be knowing it. This is something done by using DB2 utility and by your DataBaseAdministrator .

This process of taking full back-ups of your data objects is called as DB2 full image copy. It is achieved by DB2 utility COPY.

You can make full image copies of a variety of data objects. Data objects include table spaces, table space partitions, data sets of nonpartitioned table spaces, index spaces, and index space partitions.

The following statement specifies that the COPY utility is to make a full image copy of the TABSPACE table space in database DATABASE.

COPY TABLESPACE TABSPACE.DATABASE

The COPY utility writes pages from the table space or index space to the output data sets.

So, if you want to take a look at old data before pass, all you have to do is dump that image copy dataset from COPY Utility into normal DASD file on disk.

There is also something called as incremental image copy, this as it name suggest does not take complete copy but only the records which has changed (Insert/Update/Delete) from last run .

The information of this COPY Utility can be found on the DB2 catalog table SYSIBM.SYSCOPY 

More on how JCL'S for DB2 Utility looks and how it works will be covered later in DB2 utility post which I will be doing shortly.

 

2 comments:

Anonymous said...

Nice..Thank you Nithin..

Anonymous said...

Very helpful.
Thank you for info.

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