Solved. Because this is a 7.4 version and we used with oids by default, I can use the oids instead of the ctid to remove the duplicates.
Thanks. Edward W. Rouse -----Original Message----- From: pgsql-sql-ow...@postgresql.org [mailto:pgsql-sql-ow...@postgresql.org] On Behalf Of Edward W. Rouse Sent: Tuesday, August 10, 2010 4:43 PM To: pgsql-sql@postgresql.org Subject: Re: [SQL] Duplicate rows I am trying to test this but get an error. select ctid, * from test where id < 3000000 order by id, ctid; ERROR: could not identify an ordering operator for type tid HINT: Use an explicit ordering operator or modify the query. If I do a select I get this: select ctid, * from test where id < 3000000 order by id; ctid | id | activated | wake_up_time (108,22) | 316 | f | (36,17) | 316 | f | (used 2 rows only for brevity And when I tried max(ctid) I got: ERROR: function max(tid) does not exist HINT: No function matches the given name and argument types. You may need to add explicit type casts. I appreciate all the help and this feels like I'm almost there. Thanks Edward W. Rouse -----Original Message----- From: pgsql-sql-ow...@postgresql.org [mailto:pgsql-sql-ow...@postgresql.org] On Behalf Of Andreas Kretschmer Sent: Tuesday, August 10, 2010 3:45 PM To: pgsql-sql@postgresql.org Subject: Re: [SQL] Duplicate rows Edward W. Rouse <ero...@comsquared.com> wrote: > Is there any way to remove a duplicate row from a table? Not my db but I have > to work with it. On version 7.4 right now. > How to select the right records? You can try to use the ctid-column, see my simple example: test=# select * from dups ; i --- 1 1 1 2 2 3 4 (7 Zeilen) Zeit: 0,145 ms test=*# delete from dups where (ctid, i) not in (select max(ctid), i from dups group by i); DELETE 3 Zeit: 0,378 ms test=*# select * from dups ; i --- 1 2 3 4 (4 Zeilen) Andreas -- Really, I'm not out to destroy Microsoft. That will just be a completely unintentional side effect. (Linus Torvalds) "If I was god, I would recompile penguin with --enable-fly." (unknown) Kaufbach, Saxony, Germany, Europe. N 51.05082°, E 13.56889° -- Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-sql -- Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-sql -- Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-sql
