alonso wrote: > I've got it, but I don't know the reason of it. > In the database table the records have duplicated and I've > two rows for > every primary key - with different OIDs. > Very strange however... Very strange indeed. Are you positive that there is a primary key constraint on the column? Can you show some evidence? > Is there any safe method to get rid of only one of each > duplicated row? If "id" is your "primary key": DELETE FROM test USING test a WHERE test.id = a.id AND test.oid > a.oid; Yours, Laurenz Albe ---------------------------(end of broadcast)--------------------------- TIP 4: Have you searched our list archives? http://archives.postgresql.org/