This script uses a hash join -- the most efficient way of joining huge tables -- to find duplicate rows. It has been tested on Oracle 6.0 to Oracle 9i v2, and it works in all of those versions.
-- Set hash join enabled DELETE FROM <table> WHERE rowid IN (SELECT t1.rowid FROM <table> t1, <same-table> t2 -- primary key is (a1, a2) WHERE t1.a1 = t2.a1 AND t1.a2 = t2.a2 AND t1.rowid < t2.rowid) /
Una S. writes: This one confuses me. If there is a prmary key on cols (a1, a2), how can there possibly be more than one row with the same values for a1 and a2 in the table to begin with?
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