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Re: Mechanics of Select

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As others have suggested my big problem with the function I wrote was that I had made it Volatile instead of Immutable (it is no doubt suffering from code bloat as well). That made all the difference. Curiously though - I tried it just with the date_trunc function and it was just as slow as my old Volatile function.

select * from track where datetime >= '2007-04-01' and datetime < date_trunc('month','2007-04-01'::timestamp)+interval '1 month'; was about 55s select * from track where datetime >= '2007-04-01' and datetime < first_day_next_month('2007-04-01'); was about 36s

cheers

Greg Smith wrote:
On Sun, 10 Feb 2008, Willem Buitendyk wrote:

I have the following function that returns the first day of the next month from whatever date is inserted.

See if you can do this with date_trunc instead to avoid calling a function, which avoids the whole thing. The first day of next month is:

select date_trunc('month',now())+interval '1 month';

I'd be curious how the runtime using that compares with the plpgsql version you've done.

--
* Greg Smith gsmith@xxxxxxxxxxxxx http://www.gregsmith.com Baltimore, MD



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