On Thu, Aug 28, 2003 at 17:10:31 -0700, Ken Geis <[EMAIL PROTECTED]> wrote:
The query I want to run is
select stock_id, min(price_date) from day_ends group by stock_id;
The fast way to do this is:
select distinct on (stock_id) stock_id, price_date order by stock_id, price_date;
Not according to the optimizer! Plus, this is not guaranteed to return the correct results.
Unique (cost=3711244.30..3795942.42 rows=6366 width=8)
-> Sort (cost=3711244.30..3753593.36 rows=16939624 width=8)
Sort Key: stock_id, price_date
-> Seq Scan on day_ends (cost=0.00..361892.24 rows=16939624 width=8)
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