Re: Streams advice

Geoff Muldoon wrote:

> Both source and destination databases are on the same RAC cluster,

You need to explain this as it makes no sense. Replicating data within the same database? Why?

 > but we
> will probably also want to additionally replicate to our dev copy of the
> destination database on a separate (same version and O/S) RAC cluster.

This makes sense but since it doesn't need to be real-time why not just clone with RMAN?

> What appears to be our likely method is archive-log downstream capture (to
> minimise business hours load on the OLTP instances) and using the
> PREPARE_TABLE_INSTANTIATION options (as capture is required for only about
> half the columns of about a fifth of the tables in a single source
> schema).

And here comes the fun.

You are going from a RAC cluster which means each and every node has its own redo log thread which means you need to have streams running on each node.

Unless you have some need for the complexity of publish-transform-subscribe I'd take a serious look at using Change Data Capture. It is far easier to implement. Also make sure that you do the following:

alter database force logging;
alter database add supplemental log data;

-- 
Daniel A. Morgan
University of Washington
damorgan_at_x.washington.edu (replace x with u to respond)
Puget Sound Oracle Users Group
www.psoug.org