[fdo-internals] Motion: Vote on FDO RFC 38 - SHP multi-polygons

[Haris Kurtagic]

+1

Haris

 

From: fdo-internals-bounces at lists.osgeo.org
[mailto:fdo-internals-bounces at lists.osgeo.org] On Behalf Of Orest
Halustchak
Sent: Tuesday, September 08, 2009 3:33
To: FDO Internals Mail List
Subject: [fdo-internals] Motion: Vote on FDO RFC 38 - SHP multi-polygons

 

Hi,

 

There were no further comments on this RFC:
http://trac.osgeo.org/fdo/wiki/FDORfc38 - Multi-polygon support for SHP.

 

I would like to motion a vote to accept this RFC.

 

Thanks,

Orest.

 

From: fdo-internals-bounces at lists.osgeo.org
[mailto:fdo-internals-bounces at lists.osgeo.org] On Behalf Of Orest
Halustchak
Sent: Thursday, August 27, 2009 4:50 PM
To: FDO Internals Mail List
Subject: [fdo-internals] Back to FDO RFC 38 - SHP multi-polygons

 

Hi,

 

Regarding: http://trac.osgeo.org/fdo/wiki/FDORfc38 - Multi-polygon
support for SHP.

 

In our last discussions on this RFC, there was concern about performance
impact.

 

Dan has done some prototype performance testing to determine the impact
of this proposed change. He used some datasets that included complex
multi-polygons including Norway data and Australia data that had
detailed multi-polygons for all the islands (100's of loops for each
feature). Following are some statistics with before and after timings.
With each of these datasets, the time to render on the screen was much
longer than these load times and there is no difference that an end user
would see in these cases. 

 

Australia: 9 multipolygon features with 3 of them having between 800 and
900 polygon loops each, others averaging about 100 loops each.

      .015 seconds to .125 seconds

Europe: 54 multipolygon features with Norway having 862 loops, with
others of 653, 509, 359 loops, and the rest averaging about 100 loops
each.

      .016 seconds to .17 seconds

Queensland parcels: 2,000,000 polygons

      Unchanged at 1.6 seconds

 

So, yes it takes longer to process, but the overall timings are still
sub-second for the complex cases. There is also no impact on cases of
regular polygons.

 

Dan will be back from his vacation soon and will be able to do the
implementation. So, I'd like to get to a vote on this if nobody has
objections.

 

Thanks,

Orest.

 

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