On Dec 5, 2008, at 1:02 PM, Paul Ramsey wrote:
add
wkb_geometry && SetSRID('BOX3D(-162 55,-161 56)'::box3d,4326)
to your where clause to engage the index.
P
Do you mean just that, without the st_relate? That gives exactly the
same results as st_intersects, though may be a little faster since it
skips the full intersection test.
Or replace the st_intersects half? Again, probably slightly faster.
Doesn't help the st_relate half in a large box selection.
Well, that works:
ST_relate(wkb_geometry, SetSRID('BOX3D(-162 55,-161 56)'::box3d,
4326),
'T********')
But it's painfully slow - looks like relate doesn't do an index
bounding box
test.
... added a normal intersect (it's a superset of what I want) and let
short-circuit logic take care of the initial selection:
ST_Intersects(wkb_geometry, SetSRID('BOX3D(-162 55,-161 56)'::box3d,
4326))
AND ST_relate(wkb_geometry, SetSRID('BOX3D(-162 55,-161 56)'::box3d,
4326),
'T********')
That's reasonably fast, for a small box at least. It will likely
slow down
on a larger box.
-----
William Kyngesburye <kyngchaos*at*kyngchaos*dot*com>
http://www.kyngchaos.com/
"Those people who most want to rule people are, ipso-facto, those
least
suited to do it."
- A rule of the universe, from the HitchHiker's Guide to the Galaxy
_______________________________________________
postgis-users mailing list
postgis-users@postgis.refractions.net
http://postgis.refractions.net/mailman/listinfo/postgis-users
_______________________________________________
postgis-users mailing list
postgis-users@postgis.refractions.net
http://postgis.refractions.net/mailman/listinfo/postgis-users
-----
William Kyngesburye <kyngchaos*at*kyngchaos*dot*com>
http://www.kyngchaos.com/
"Those people who most want to rule people are, ipso-facto, those
least suited to do it."
- A rule of the universe, from the HitchHiker's Guide to the Galaxy
_______________________________________________
postgis-users mailing list
postgis-users@postgis.refractions.net
http://postgis.refractions.net/mailman/listinfo/postgis-users
