Thomas Kellerer <spam_ea...@gmx.net> writes:
> DELETE FROM dupes
> WHERE id NOT IN (SELECT min(b.id)
> FROM dupes b
> GROUP BY first_name, last_Name
> HAVING count(*) > 1);
Doesn't that kill the non-duplicates too?
> Why does the usage of the CTID column change the plan so drastically?
IIRC, type tid doesn't have any hash support.
regards, tom lane
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