Re: Sybase <-> Oracle Replication

Alex wrote:

> Dear netters,
>
> We are in the process of migrating some of our applications from Sybase
> (12.5) to Oracle (10g), and are looking for a transitional plan for
> keeping the systems running in parallel.
>
> Specifically, we plan on having 3 database servers (simplified
> scenario) as follows:
>
> Server #1 (Sybase) - main databases
> Server #2 (Sybase) - supplemental databases
> Server #3 (Oracle) - migrated main databases (mostly, replica of #1)
>
> Sybase is runing on Solaris, Oracle will be running on AIX.
>
> In our current environment, we need to maintain the following data
> movements:
> Server #1 -> Server #3 (one way).
> This one is for when both servers go live and we begin migrating
> applications to be consumers of data in Oracle, rather than Sybase.
> Existing applications will continue working with Sybase until they are
> migrated, and data is also populated on the Sybase server through a
> number of data feeds. For the time being, Oracle Server #3 will be a
> read-only database, that needs to be updated on a regular basis, in
> near real-time (up to 1 hour delay is acceptable). Anticipated volume
> is several million rows of data per day, more during peak times, but
> otherwise -- spread throughout the day. Data structures between Sybase
> #1 and Oracle #3 will be fairly similar after the migration.
>
> Server #1 <-> Server #2 (two way).
> In addition to getting external feeds, server #1 will also be receiving
> data from Server #2. The volume of data is not large -- data on Server
> #2 is modified either through some batch processing (up to 100,000 rows
> per day) or via manual data entry (mostly, corrections, etc., up to
> about 10,000 rows per day). The data movement also allows for some
> latency, up to 1 hour is acceptable.
> Data structures are different between Server #1 and Server #2, some
> massaging/transformation is required.
>
> We are looking to implement some sort of replication to fit both of
> these requirements. For options we are looking at:
> - Sybase Replication Server + DirectConnect to Oracle
> - Informatica
> - bcp out/bcp in or bcp out/sql loadr in
> - Oracle Transparent Gateway
> - Others???
>
> In either case, replication will be for changes made since last
> replication was run. There may be additional conditions imposed on what
> gets replicated, further limiting the amount of data to be replicated.
> A complete refresh of data is not an option, due to large overall
> volume of data stored in all databases.
>
> What are the recommendations? Do you know if anybody has evaluated
> these (and other) options for pros/cons -- as far as ease of
> implementation, cost, database changes' requirements, additional
> hardware requirements, etc.?
>
> Thank you in advance!
>
> --Alex

In 10g either Streams or DataGuard.

-- 
Daniel A. Morgan
University of Washington
damorgan_at_x.washington.edu
(replace 'x' with 'u' to respond)