Accessing history tables

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shanthic2003
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Joined: Sat Sep 08, 2012 12:17 pm

Accessing history tables

Post by shanthic2003 » Sat Sep 08, 2012 12:39 pm

Hi...Could someone help me with identifying the solution with optimum performance to my problem.

I have a db2 table with 20 million records and the history table has more than 30 million records. Active and history are two different tables i.e.., they are not partitioned.

Now my requirement is that before inserting a certain value for a user in active table, i should make sure that similar attribute has not been deleted for that user in the past .ie., i should check also history table if there has been a deletion history.

My PL1 program now only checks active table. Can i extend it to checking also the history table before every insert which is growing over time? Does it cause a big performance issue? Do you have someviews how to solve it?

DikDude
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Location: usa

Post by DikDude » Sun Sep 09, 2012 1:05 am

Reading 2 tables instead of one should not be a major issue as long as the tables have keys defined that provide direct access to the row(s) needed.

If checking could read thousands of rows in these tables, there will be a performance impact.
Have a good one

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