Quick question about triggers and replication

I have a trigger on a table that mimics the MS SQL Server autonumber fields as follows:

CREATE OR REPLACE TRIGGER mySchema.myAutoNumber BEFORE INSERT ON mySchema.myTable FOR EACH ROW WHEN (new.autoid is null) begin
  select mySeq.nextval into :new.autoid from dual; end;

This table is being replicated to a remote database as an updatable materialized view (using primary key). This MV site is a passive standby site and is only used in the times of scheduled outages and not so scheduled outages!

The above trigger is on both the master and MV base table. The master site has all even autonumbers, the MV site has all odd autonumbers.

I have googled around and have read that triggers on MV base tables fire when they receive a record from the master site. Later I read on another site that not all triggers on base tables fire.

Also found that the way to stop a trigger firing is by including "DBMS_REPUTIL.FROM_REMOTE = FALSE" eg

CREATE OR REPLACE TRIGGER mySchema.myAutoNumber BEFORE INSERT ON mySchema.myTable FOR EACH ROW WHEN (new.autoid is null) begin

   IF DBMS_REPUTIL.FROM_REMOTE = FALSE THEN          select mySeq.nextval into :new.autoid from dual;    END IF;
end;

My questions are:

• do triggers on a MV base table always fire when a record is pulled from the master table?
• if not, then given my trigger above, the AUTOID field will not be null when it is pulled over from the master site, hence the trigger logic would suggest that it would not fire anyway - have I understood this correctly?
• can anyone give me a quick example of a trigger that would fire each time a record is replicated to the target site?

Many thanks

Edwinah63 Received on Mon Mar 27 2006 - 22:30:31 CST