From: | CoL <col(at)mportal(dot)hu> |
---|---|
To: | pgsql-performance(at)postgresql(dot)org |
Subject: | Re: Feature request: smarter use of conditional indexes |
Date: | 2004-03-03 23:37:46 |
Message-ID: | c25q4g$1ei7$1@news.hub.org |
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Thread: | |
Lists: | pgsql-performance |
hi,
John Siracusa wrote, On 3/3/2004 20:56:
> Given an index like this:
>
> CREATE UNIQUE INDEX i1 ON t1 (c1) WHERE c1 IS NOT NULL;
>
> and a query like this:
>
> SELECT * FROM t1 WHERE c1 = 123;
>
> I'd like the planner to be smart enough to use an index scan using i1. Yes,
> I can change the query to this:
>
> SELECT * FROM t1 WHERE c1 = 123 AND c1 IS NOT NULL;
>
> In which case the index will be used, but I shouldn't have to. More
> practically, since a lot of my SQL is auto-generated, it's difficult to make
> this query change just in the cases where I need it. And I'm loathe to
> change every "column = value" pair in my auto-generated SQL into a double
> pair of "(column = value and column is not null)" It's redundant and looks
> pretty silly, IMO.
how about: CREATE UNIQUE INDEX i1 ON t1 (c1);
WHERE c1 IS NOT NULL in this case what is the point of doing this?
You do not need this condition.
C.
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