I'm sure this is a fairly common desire, however I haven't found any
good answers yet. We have some applications that do not yet demand
any of the scalability, availability or performance features of
enterprise edition, except that we want a way to have a read only copy
of the database on a physically separate machine.
The requirements for the copy:
- should be almost up to date (near instant desired, 5-10 minutes is ok)
- does not need to be synchronous with the primary database
- needs to be accessible for read only queries
- no automated failover required, manual failover needs to be
possible, loss of 5-10 minutes data is acceptable.
- needs to be able to automatically replicate new tables and other
basic DDL changes in addition to DML changes.
- both the primary and the copy will be located in the same data center
The current business requirements for this application make using
enterprise edition a very hard sell from the cost perspective right
now, just to get the ability to have some type of read only
replicated/standby/etc. database. This is especially true given that
Microsoft SQL Server includes reasonably usable replication support in
their standard edition. However, there is a possibility of future
requirements justifying Oracle EE, and a general desire to use Oracle
for the application for ease of future scaling and migration.
Options I am aware of:
- What is described as "basic replication" in Oracle's product family
comparison list, with a note of "Updateable materialized view site".
This doesn't seem to be an attractive option since, from what I
understand these need to be setup for each table, and do not support
DDL changes. I am, however, having a very hard time mapping this
feature in Oracle's product family comparison list to what it actually
means. Searching for "basic replication" in the 10g docs does not
return a single result.
- Create a standby database in manual recovery mode and setup scripts
to copy the redo logs from the primary database. As I understand it,
it is possible to do this and have the database online in read only
mode. Not overly attractive since it is reinventing the wheel.
- some third party product that can do something resembling the
previous option. I don't have any good leads on possible products
that are cost effective for this.
- implementing it manually with db links and a bunch of triggers and
stuff. Even less attractive than copying the redo logs over in terms
of reinveneting the wheel and dealing with all the corner cases.
Any other suggestions?
Thanks.
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Received on Sun Sep 26 2004 - 16:24:15 CDT
