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-owner@postgresql.org [mailto:pgsql-sql-owner@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 <erouse@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
---1112234
(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
---1234
(4 Zeilen)
Andreas
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