"Marshall, Steve" <[EMAIL PROTECTED]> wrote:

> the first query would be optimized using 
> constraint exclusion, while the second query would not:
> SELECT * FROM test_bulletins WHERE created_at > '2006-09-09 
> 05:00:00+00'::timestamptz;
> SELECT * FROM test_bulletins WHERE created_at > '2006-09-09 
> 05:00:00+00'::timestamptz + '0 days'::interval;

Hmmm... CE seems to be still not enough to optimize complex expressions.
If I added the wrapper function, it worked.

CREATE FUNCTION timeadd(timestamptz, interval) RETURNS timestamptz
    AS $$ SELECT $1 + $2; $$ LANGUAGE sql IMMUTABLE;

SELECT * FROM test_bulletins WHERE created_at >
    timeadd('2006-09-09 05:00:00+00', '0 days');

I noticed that we should be careful about CE with prepared statements
and functions. Seamless partitioning requires more works.

ITAGAKI Takahiro
NTT Open Source Software Center

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