Mainframe, MVS and zOS Discussion

I have one interview question if anybody knows answer:

There is a DB2 table in both TEST and Prod regions,

I wanted to compare both and restore test table with prod wherever it is not matching.

How can we do in COBOL-DB2 Program?

One easy way to do that is - unload DB2 tables to datasets. Bring them to a single given region - either to Prod or Test. Now it's a two-file comparison situation.