Best way to clone DB-Tables

Question

I need to clone (make a 1to1 copy of) several Tables in our Oracle DB into another Oracle DB. Both DBs are running under Oracle version 11.2.0.3

Problems are:

1. Tables (together) are quite large (> 20gb)
2. Must be a real "Snapshot". DB may change during cloning process
3. Realisation must be (of course) damn quick

I came across the DB-Link technology, which seems feasible here. But my question is: How can I make sure, that ALL Tables are consistent after the cloning process? I mean this scenario:

1. Copy Table A
2. Copy Table B
3. Source Table A and Table C changes
4. Copy Table C

Then my copy Table C contains data, which is NOT present in copy Table A, which might be a constraint violation (logically). How can I avoid this? How do I make a real snapshot of 40 Tables? Is there something like a "revision" of the whole DB? How would the DB-Link-Query then look like?

Answer 1

I suggest you investigate the export utility of Oracle itself. You can impose that the "dump" of the set of tables you are interested in is consistent in terms of transaction, too.

More details here.

Considering you are using 11g I suppose that with "exp tool" you mean the "Data Pump Exp" and not the "legacy exp/imp Utility"?

See the differences here.

If this is not the case try switching to the Data Pump which was designed specifically to cope with large datasets, and may be further tuned to squeeze some extra performance.