From: Greg Stark <gsstark@mit.edu>
To: Achilleus Mantzios <achill@matrix.gatewaynet.com>
Cc: Greg Stark <gsstark@mit.edu>
Cc: pgsql-sql <pgsql-sql@postgresql.org>
Subject: Re: Gist indexes on int arrays
Date: 04 Mar 2003 10:28:06 -0500
Message-ID: <87smu3kv7d.fsf@stark.dyndns.tv> (raw)
In-Reply-To: <Pine.LNX.4.44.0303040934040.26498-100000@matrix.gatewaynet.com>
References: <Pine.LNX.4.44.0303040934040.26498-100000@matrix.gatewaynet.com>
Achilleus Mantzios <achill@matrix.gatewaynet.com> writes:
> Moreover if your array element positions that you want to compare
> against(e.g attr_a[1], or attr_b[n], where n is the last element) are
> known, then you could have a function "first" that returns
> the first element ...
Except that's precisely what I'm *not* doing. I'm treating the arrays as sets
and looking for records where the set contains a given value. This is a
denormalized table generated nightly from fully normalized raw data.
So to simplify it, the query might have clauses like:
WHERE foo_id = 900
AND '{5}'::integer[] ~ attribute_set_array
Right now I have a btree index on (foo_id).
Can I have a GiST index on (foo_id, attribute_set_array) and have it be just
as fast at narrowing the search to just foo_id = 900 but also speed up the ~
operation?
Incidentally, it seems odd that there isn't an operator like ~ but optimized
specifically for searching for a single item. It seems awkward and possibly
unnecessarily slow to have to construct an array for the search parameter
every time.
--
greg
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To: pgsql-sql@postgresql.org
Cc: gsstark@mit.edu, achill@matrix.gatewaynet.com
Subject: Re: Gist indexes on int arrays
In-Reply-To: <87smu3kv7d.fsf@stark.dyndns.tv>
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