[postgis-users] Array Size Error

[Paragon Corporation]

Yes we need an aggregate ConvexHull like upcoming SQL Server 

http://msdn.microsoft.com/en-us/library/ff929295%28v=sql.110%29.aspx

 

 and Oracle has (since could it be 9.2 :-) )  --
http://download.oracle.com/docs/cd/B10501_01/appdev.920/a96630/sdo_aggr.htm

 

Regina

http://www.postgis.us <http://www.postgis.us/> 

 

 

 

  _____  

From: postgis-users-bounces at postgis.refractions.net
[mailto:postgis-users-bounces at postgis.refractions.net] On Behalf Of Paul
Ramsey
Sent: Tuesday, July 26, 2011 1:44 PM
To: PostGIS Users Discussion
Cc: PostGIS Users
Subject: Re: [postgis-users] Array Size Error

 

The problem is you are collecting the whole table into memory before running
the hull operation. There is just an upper limit to the size of tables you
can use that trick on. The solution, says the software developer, is smarter
software, like a convex hull aggregate that builds the hull progressively,
instead if having to first collect all the inputs.

P.


On 2011-07-26, at 2:44 AM, Paul & Caroline Lewis <paulcaz80 at hotmail.com>
wrote:

Hi All,
The following error has me lost as to finding the solution:

****************************************************************************
*
ERROR: array size exceeds the maximum allowed (1073741823)
---------- Error----------------
ERROR: array size exceeds the maximum allowed (1073741823)
SQL state: 54000
****************************************************************************
*

It happened when using this SQL:

****************************************************************************
*
SELECT ST_ConvexHull(ST_Collect(ST_Force_2D(geom))) FROM table001
****************************************************************************
*
This table has 62 million 3D point geometry records, which is one of the
small tables I want to use this function on. 
While the server we are running is quite powerful (32GB RAM), we have edited
a lot of system/DB memory settings but I cannot trace any changes we made to
the array size mentioned in the error.
It also seems this query is very similar to this thread:

 
<http://postgis.refractions.net/pipermail/postgis-users/2010-March/026215.ht
ml>
http://postgis.refractions.net/pipermail/postgis-users/2010-March/026215.htm
l

However, I cannot ascertain if a solution was found in this thread and was
wondering if anyone has seen this problem.
The error's array size is 1GB I believe (if the number is bytes) but we have
not changed any settings that reference 1GB, does anyone know where this
array limit error is coming from. I have a similar system to that mentioned
in the thread above but for a Postgresql 9 install. The DB is fine other
than this error where more complex bounding box queries on the 3D geoms are
working.

Any help/info would be much appreciated.

Paul 

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