in reply to Connection Pooling
I don't know if this will help in your case, but I had a few years ago a somewhat similar case: a euro migration of a relatively large database with about 120 or 130 tables having monetary values to be converted to the new currency. My responsibility was to validate the data quality after the migration. What we did is simply to dump the tables (or the relevant fields of the tables) into flat CSV files before and after the migration and then just read the files in parallel to compare the monetary values and check their conversion. This turned out to be more practical and much faster than using database indexes to access the data. But, because of the nature of the migration, we were guaranteed to have the data dumped in the same order into the files, making further processing very easy. This might or might not apply to your case.