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List: postgis-users
Subject: [postgis-users] Indexes not being used
From: "Pedro Doria Meunier" <pdoria () netmadeira ! com>
Date: 2007-03-31 18:57:54
Message-ID: 001001c773c6$80ba2470$822e6d50$ () com
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Hi all (with a special wink to Regina ;- )
This is the query not using indices:
SELECT parish,county,geometry FROM pt_madeira_toponymy as t WHERE
parish=upper('se') AND
t.geometry && geomfromtext('POINT(-16.9213592631455
32.6437878212273)',4326) AND
intersects(geomfromtext('POINT(-16.9213592631455 32.6437878212273)',4326),
t.geometry);
As you can plainly see it checks if a point is inside some polygon.
EXPLAIN ANALYZE returns this:
"Seq Scan on pt_madeira_toponymy t (cost=0.00..3.03 rows=1 width=96)
(actual time=1.086..1.278 rows=1 loops=1)"
" Filter: ((parish = 'SE'::text) AND (geometry &&
'0101000020E61000009B135F33DEEB30C0FFDDAAA367524040'::geometry) AND
intersects('0101000020E61000009B135F33DEEB30C0FFDDAAA367524040'::geometry,
geometry))"
"Total runtime: 1.312 ms"
The toponymy has two indices: one for 4326 and another for 32628 using GiST.
Is the intersects function not using indices at all??
Already thankful for any ideas,
With best regards,
Pedro Doria Meunier.
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<p class=MsoNormal><span lang=EN-US>Hi all (with a special wink to Regina ;- \
)<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-US>This is the query not using \
indices:<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-US>SELECT parish,county,geometry FROM
pt_madeira_toponymy as t WHERE parish=upper('se') AND<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US> t.geometry &&
geomfromtext('POINT(-16.9213592631455 32.6437878212273)',4326) AND
intersects(geomfromtext('POINT(-16.9213592631455 32.6437878212273)',4326),
t.geometry);<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-US>As you can plainly see it checks if a point
is inside some polygon.<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-US>EXPLAIN ANALYZE returns \
this:<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US>"Seq Scan on pt_madeira_toponymy
t (cost=0.00..3.03 rows=1 width=96) (actual time=1.086..1.278 rows=1
loops=1)"<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US>" Filter: ((parish = 'SE'::text)
AND (geometry && \
'0101000020E61000009B135F33DEEB30C0FFDDAAA367524040'::geometry) AND \
intersects('0101000020E61000009B135F33DEEB30C0FFDDAAA367524040'::geometry, \
geometry))"<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US>"Total runtime: 1.312 \
ms"<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-US>The toponymy has two indices: one for 4326
and another for 32628 using GiST.<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-US>Is the intersects function not using
indices at all??<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-US>Already thankful for any \
ideas,<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US>With best regards,<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-US>Pedro Doria Meunier.<o:p></o:p></span></p>
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