[postgis-users] Very long time for a bbox/within query

[Gregory S. Williamson]

Hopeless.

I rewrote the query to pick up the FIPS boundry so there is no subselect in either the bounding box or within queries.

After waiting 6 hours with one CPU pegged I killed the process.

There is something badly wrong with postGIS if it can't process one county (complicated but a legitimate multipolygon -- Bradford Florida, FIPS 12007) and a within statement for data set (some 4.2 million rows) in 360 minutes of processing time.

The "within" operation is clearly the dog -- the bounding box query works blindingly fast.

All I need to is if there is any overlap between a county and any of the detail data. Apparently postGIS cannot tell me this.

Looks like we have to migrate back to Informix, which at least can produce answers.

;-(

Greg Williamson
DBA
GlobeXplorer LLC

-----Original Message-----
From:	David Blasby [mailto:dblasby at gmail.com]
Sent:	Tue 7/20/2004 2:42 PM
To:	PostGIS Users Discussion
Cc:	
Subject:	Re: [postgis-users] Very long time for a bbox/within query
Instead of the sub-queries try putting in the actual geometries (run
the sub-queries in psql and copy-and-paste in the results).  If it
runs fast, then its probably running the sub-query multiple times or
the type casting system is getting confused.

Next, I'd try removing the within() clause.  If it runs fast, then
you're spending a lot of time inside the within() function - are your
geometries complex?

dave
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