Monday, February 9, 2009

The cost of selecting the wrong technology

When I took my class about Oracle Streams, something called my attention, what do I use Oracle streams for, and how does it compares with Oracle Advance replication. The answer to that question is not trivial but it is important. Despite what Oracle can tell you Oracle Streams is a lot more complex and requires a lot more maintenance than Oracle Advance replication, but both of them have it's niche.

- Oracle Streams allows you to do transformations of the data as well as to partially replicate a table or a group of tables. (Mviews allows partial replication ans transformation as well)
- Oracle Replication is more suitable when you want to replicate something from site A to site B.
- Oracle Streams relies heavily on the use of keys.
- Oracle Streams is a newer technology more prompt to bugs, Oracle Advance replication has years in the market and is a proven technology.
- A single Oracle streams transaction generates multiple LCRs and the complete transaction is propagated, with advance replication only the values that change gets propagated.
- Oracle Streams can lag behind if you do not perform frequently commits in your source database.
- Oracle Streams allows you to do down streams capture which impose almost no performance impact to the source, while advance replication has an small performance penalty.

As you can see above it is important to evaluate your application when selecting any of this technologies. selecting the wrong technology just could create a maintenance nightmare that anyway is not going to satisfy your business requirements.


No comments: