Re: Polygons passed to poly_overlap have 0 pts when column is indexed using rtree

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: "Kenneth Chan" <kkchan(at)technologist(dot)com>
Cc: pgsql-hackers(at)postgreSQL(dot)org
Subject: Re: Polygons passed to poly_overlap have 0 pts when column is indexed using rtree
Date: 2002-05-29 03:29:08
Message-ID: 19946.1022642948@sss.pgh.pa.us
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> ... Turned out that npts of the
> polygon retrieved from the table is 0 (the other polygon is a constant
> and its attributes are correct). I suspect the feature might
> affect other functions that uses polygons->npts like poly_contain.
> Would anyone happens to know the identity of the offending
> function might be? TIA

It appears that the issue is not rtree itself, but the rt_poly_union
and rt_poly_inter functions, which produce "polygons" that have only
bounding boxes. Not sure whether that should be considered erroneous
or not. The dummy polygons are evidently used as internal node keys
in the rtree.

regards, tom lane

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