Hi All, I'd like to move some data from one table to another (with a possibly different schema). Straightforward solution that comes into mind is - start a transaction with serializable isolation level; INSERT INTO dest_table SELECT data FROM orig_table,other-tables WHERE <condition>; DELETE FROM orig_table USING other-tables WHERE <condition>; COMMIT; Now what if the amount of data is rather big, and the <condition> is expensive to compute? In PostgreSQL, a RULE or a stored procedure can be used to delete data on the fly, evaluating condition only once. Which solution is better? Are there other options?