Hi, You can try following query on test database to remove duplicates.
DELETE FROM isi.rcited_ref a WHERE a.ctid <> (SELECT min(ctid) FROM isi.rcited_ref b WHERE a.rart_id = b.rart_id AND a.r9 = b.r9 AND a.ra = b.ra AND a.ry = b.ry AND a.rw = b.rw AND a.rv = b.rv AND a.rp = b.rp AND a.rs = b.rs AND a.rart_id = 'A1986D733500019' ); Regards, Ketana ________________________________ From: Johann Spies <johann.sp...@gmail.com> To: "pgsql-general@postgresql.org" <pgsql-general@postgresql.org> Sent: Wednesday, 10 July 2013 5:11 AM Subject: [GENERAL] Removing duplicates I have used this method successfully on another table but this one is not working. I have a table of nearly 800 million records with some duplicates in. Here is an example: select rart_id, r9, ra, ry, rw, rv, rp, rs, ri from isi.rcited_ref where rart_id = 'A1986D733500019'; renders a result of 72 records. When I do select count(id), rart_id, r9, ra, ry, rw, rv, rp, rs, ri from isi.rcited_ref where rart_id = 'A1986D733500019' group by rart_id, r9, ra, ry, rw, rv, rp, rs, ri; It shows that there are 36 duplicates with this rart_id. So as a test I did the following (the id-field is the primary key): DELETE FROM isi.rcited_ref q WHERE EXISTS(SELECT 1 FROM isi.rcited_ref q1 WHERE q1.id != q.id AND q.rart_id = q1.rart_id AND q.r9 = q1.r9 AND q.ra = q1.ra AND q.ry = q1.ry AND q.rw = q1.rw AND q.rv = q1.rv AND q.rp = q1.rp AND q.rs = q1.rs AND q.rart_id = 'A1986D733500019' ); But that deletes none. And I cannot see what went wrong. I have also tried the same query with ctid without success: DELETE FROM isi.rcited_ref q WHERE EXISTS(SELECT 1 FROM isi.rcited_ref q1 WHERE q1.ctid < q.ctid AND q.rart_id = q1.rart_id AND q.r9 = q1.r9 AND q.ra = q1.ra AND q.ry = q1.ry AND q.rw = q1.rw AND q.rv = q1.rv AND q.rp = q1.rp AND q.rs = q1.rs AND q.rart_id = 'A1986D733500019' ); The size of the table makes it difficult to use a 'group by' method to delete all duplcates. What am I doing wrong? Regards Johann -- Because experiencing your loyal love is better than life itself, my lips will praise you. (Psalm 63:3)
