[postgis-devel] gist broken on PG 8.0

[strk at refractions.net]

Whoooaaa
The bad beast is dead!
pointArray_construct() used to allocate less space then required,
thus leaving bits exposed to everybody's pleasures.

GiST indexing is now working for LWGEOM. 

--strk;


On Fri, Sep 17, 2004 at 07:03:33PM +0200, strk at refractions.net wrote:
> On Fri, Sep 17, 2004 at 10:50:50AM +0100, Mark Cave-Ayland wrote:
> > 
> > > -----Original Message-----
> > > From: postgis-devel-bounces at postgis.refractions.net 
> > > [mailto:postgis-devel-bounces at postgis.refractions.net] On 
> > > Behalf Of strk at refractions.net
> > > Sent: 16 September 2004 16:46
> > > To: postgis-devel at postgis.refractions.net
> > > Subject: [postgis-devel] gist broken on PG 8.0
> > > 
> > > 
> > > I've been spending a good amount of time trying to debug
> > > gist indexing for LWGEOM. I now discovered the bug
> > > also show with HWGEOM (current CVS code - should be 0.9).
> > > Does anyone experience segfaults with PG8.0.0beta2 and
> > > postgis 0.9 / head CVS branches ?
> > > 
> > > Adding hooks in postgresql gist code I found out that
> > > gistchose() get a Page as argument which has a 
> > > maxoffsetnumber == 0, which makes code around gist.c:1477 
> > > loop forever (up to memory fault).
> > > 
> > > Any help ?
> > > 
> > > --strk;
> > 
> > 
> > Hi strk,
> > 
> > I've just done a fresh install with PG 8.0b2 and PostGIS 0.9. I loaded
> > in an 8,000 geometry shapefile, build an GiST index, and tried a few
> > queries without any problems. I also ran through the test_estimation.pl
> > several times, and again didn't experience any crashes.
> 
> mmm.. dragons here...
> I got segfaults just creating the index on an empty table
> and adding a couple of POINT geoms (sometimes more then 2 but
> no more then 10).
> The faults under LWGEOM are more tested (HWGEOM issue 
> was new to me). The maxoffsetnumber thing is verified under
> LWGEOM, second point added is enough to exploit.
> 
> --strk;
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