[postgis-devel] ST_Value out of memory

[Jorge Arévalo]

On Mon, Jan 17, 2011 at 7:50 PM, Etienne Bellemare <etiennebr at gmail.com> wrote:
> Hi all,
>
> I have points tables containing 1-2M (lidar) points and a raster containing
> 750k tiles of 100x100 pixels. So I'd like to get the value of the raster for
> each point coordinate. But I run out of memory. I was quite surprised to see
> it was actually possible to run out of memory with PostgeSQL as I thought it
> would switch to disk when the 3Gb RAM memory would fill (I've seen the
> process go as high as 1,7 Gb according to the task manager). But indeed it
> seems it's possible to run out of memory. The disk containing the db still
> have 900 Gb of free space.  The solutions I've seen so far on the web look
> more like production database solutions. Mine is actually for research
> purpose : I'm the only one making transactions on it so I don't have many
> queries running at the same time. Furthermore, I'm not a db ninja, so
> messing around with all these settings... I wasn't sure to say the least.
>
> I couldn't isolate a single factor to the bug. Of course, point table size
> looks like a factor, the biggest table succeding was 467Mb ( I have tables
> of size up to 600Mb). But some 200 Mb tables ran out of memory while other
> went OK. Other factor seems to be the tiles (low number of tiles
> intersecting the point table, more likely to not run out of memory.) So, I'm
> calling for some input on either tests to perform to isolate the bug factors
> or to avoid running out of memory.
>
> Etienne
>
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>
>

Hi Etienne,

Could you please provide a dump of one table causing the error?

Best regards,

-- 
Jorge Arévalo
Internet & Mobilty Division, DEIMOS
jorge.arevalo at deimos-space.com
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