Re: Index isn't used during a join.

When grilled further on (Wed, 11 Jan 2006 07:26:59 -0700),
Robert Creager <Robert_Creager(at)LogicalChaos(dot)org> confessed:

>
> weather-# SELECT *, unmunge_time( time_group ) AS time,
> weather-# EXTRACT( doy FROM unmunge_time( time_group ) )
> weather-# FROM minute."windspeed"
> weather-# JOIN doy_agg ON( EXTRACT( doy FROM unmunge_time( time_group ) ) = doy )
> weather-# WHERE unmunge_time( time_group ) > ( now() - '24 hour'::interval )
> weather-# AND doy BETWEEN EXTRACT( doy FROM now() - '24 hour'::interval)
> weather-# AND EXTRACT( doy FROM now() )
> weather-# ORDER BY time_group;

The more I think about it, the more I believe PG is missing an opportunity. The query is adequately constrained without the BETWEEN clause. Why doesn't PG see that? I realize I'm a hack and by db organization shows that...

The query is wrong as stated, as it won't work when the interval crosses a year boundary, but it's a stop gap for now.

Cheers,
Rob

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