[postgis-users] trying to debug segmentation violation

[Jessica M Salmon]

Mark,

>Unfortunately an intermittent Signal 11 tends to indicate a hardware
problem, normally bad memory.

It is intermittent in that it happens only on a small percentage of the
data, but it happens very consistently only on these points. This suggests
to me that bad memory cannot be responsible. But I am downloading memtest86
to try tonight, just in case.

Thanks for your input.

-Meghan


                                                                           
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                                       RE: [postgis-users] trying to debug 
             09/21/2005 10:46          segmentation violation              
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> -----Original Message-----
> From: postgis-users-bounces at postgis.refractions.net
> [mailto:postgis-users-bounces at postgis.refractions.net] On
> Behalf Of Jessica M Salmon
> Sent: 21 September 2005 17:04
> To: postgis-users at postgis.refractions.net
> Subject: [postgis-users] trying to debug segmentation violation
>
>
> A plpsql function I wrote is starting to occasionally kick me
> off with a signal 11 error code. It seems to occur while
> calculating a 300m buffer around the transformed point
> transform(geomfromewkt('SRID=4326;POINT(-118.335235595703
> 36.8628845214844)', 102008)  When I do this at the command
> line (from the same geometry in memory as the function was
> accessing), it gives a result just fine. The function
> calculates thousands upon thousands of these just fine, but
> objects to this one and one other.
>
> I have two questions:
> 1) How can I obtain more information on where exactly the
> segV is occurring? I know where it happens in my code, but
> since it seems to happen in a geos function, I cannot use
> print statements to get any more detail.
> 2) What are the common causes of this sort of error?
>
> Thanks for any responses,
> Meghan


Hi Meghan,

Unfortunately an intermittent Signal 11 tends to indicate a hardware
problem, normally bad memory. If you are using an x86 processor, then it's
worth letting memtest86 (http://www.memtest86.com/) run overnight to see if
it finds any errors, and if so, replace the faulty module and see if the
problem still occurs.


Kind regards,

Mark.

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