I'm preparing a fairly large 7.4.6 DB for trigger-based replication. I'm looking for ways to minimize my impact on the existing schema & data and uptime. This replication solution requires every table to have a primary key. Rather than adding a new key column and index for the pkey, it's appealing to just to reuse existing unique indices on non-null columns. Are there are any known or obvious gotchas associated with transforming a unique index on a non null column into a primary key via this sql? update pg_index set indisprimary = 't' where indexrelid = <my non-null unique index oid> TIA. Ed ---------------------------(end of broadcast)--------------------------- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq