Hi,
I've read through the relevant documentation on distributed transactions for PostgreSQL 8.2.5 but it leaves me with more questions than answers. It is unclear to me how SQL statements can be executed at remote nodes from a single coordinator and then use distributed two-phase commit (via 'prepare transaction tid' and 'commit prepared'). I worked at Oracle in the distributed database group and could do things like the following using PL/SQL, where we insert the same row into the same table on three different nodes, including the local one:
insert into foo ....
COMMIT
This sequence will insert a row into all three tables and do the distributed atomic commitment.
My question is this: How does PostgreSQL 8.2.5 execute DML statements (insert, update, delete, select) on remote nodes as part of the same transaction? Where is the syntax specified? Or, is there a different model supported? It's sort of like the synchronous multi-master replication mentioned in Chapter 24. I'm looking for an integrated solution.
Brian Oki, Ph.D.
Cisco Systems, Inc.