[postgis-users] 2.1.6 Released

Fri Mar 27 04:48:13 PDT 2015

Thanks Rémi. They do indeed appear to be compressed using your two tests.

And the improved SQL is about 20% faster.
Thanks!

From: postgis-users-bounces at lists.osgeo.org [mailto:postgis-users-bounces at lists.osgeo.org] On Behalf Of Rémi Cura
Sent: Thursday, March 26, 2015 8:37 PM
To: PostGIS Users Discussion
Subject: Re: [postgis-users] 2.1.6 Released

Hum you can do a simple test,
for the table you are using,
look at the pgpoint column type number (called pcid)
You can know this like this

    SELECT pc_astext(pt)
    FROM xyz_patches, pc_explode(pa) as pt
    LIMIT 1
Know look into public.pointcloud_formats, the xml schema corresponding to the pcid you found.
You should see if it is compressed.
Another method is to take a patch and compare it with the uncompressed version.
SELECT block_id, pa, pc_uncompress(pa)
FROM patches
LIMIT 1

Here is the correct way to write your querry anyway, you should see a great speed up.
--recent postgres
SELECT block_id , pc_get(pt, 'X') as x, pc_get(pt, 'Y') as y, pc_get(pt, 'Z') as z
FROM xyz_patches, pc_explode(pa) as pt
--old postgres
WITH points AS (
SELECT block_id, pc_explode(pa) as pt
FROM xyz_patches, pc_explode(pa) as pt
)
SELECT block_id , pc_get(pt, 'X') as x, pc_get(pt, 'Y') as y, pc_get(pt, 'Z') as z
FROM points
Cheers,
Rémi-C

2015-03-26 19:09 GMT+01:00 Jonathan Moules <J.Moules at hrwallingford.com<mailto:J.Moules at hrwallingford.com>>:
Hi Rémi,
Thanks for the reply and information.

I’m afraid I inherited this database and don’t know much about it (or pointcloud).

Looking into though, I doubt it’s compressed, we extract the data with:
select block_id , pc_get(pc_explode(pa), 'X') as x, pc_get(pc_explode(pa), 'Y') as y, pc_get(pc_explode(pa), 'Z') as z from xyz_patches

so using pc_get rather than pc_uncompress.

On the other hand, there are 6 entries in pointcloud_formats which all have the “<Metadata name="compression">dimensional</Metadata>” line set. But I can’t decipher the documentation well enough to know if the data actually uses it.

Cheers,
Jonathan

From: postgis-users-bounces at lists.osgeo.org<mailto:postgis-users-bounces at lists.osgeo.org> [mailto:postgis-users-bounces at lists.osgeo.org<mailto:postgis-users-bounces at lists.osgeo.org>] On Behalf Of Rémi Cura
Sent: Thursday, March 26, 2015 5:33 PM
To: PostGIS Users Discussion
Subject: Re: [postgis-users] 2.1.6 Released

Hey,
if you use the compression of patch and sensible xml schema,
you should already have a 1:2 to 1:4 compression of the point size.
(compared to binary ply in my case)
Cheers,
Rémi-C

2015-03-26 18:05 GMT+01:00 Jonathan Moules <J.Moules at hrwallingford.com<mailto:J.Moules at hrwallingford.com>>:
Hi Paul,
I suspect I know the answer to this (“no”), but to confirm, is the disk saving for points going to apply to points stored using the pointcloud extension in a postgis database?

Thanks,
Jonathan

From: postgis-users-bounces at lists.osgeo.org<mailto:postgis-users-bounces at lists.osgeo.org> [mailto:postgis-users-bounces at lists.osgeo.org<mailto:postgis-users-bounces at lists.osgeo.org>] On Behalf Of Paul Ramsey
Sent: Friday, March 20, 2015 5:45 PM
To: PostGIS Users Discussion
Subject: [postgis-users] 2.1.6 Released

The 2.1.6 release of PostGIS is now available<http://download.osgeo.org/postgis/source/postgis-2.1.6.tar.gz>.

The PostGIS development team is happy to release patch for PostGIS 2.1, the 2.1.6 release. As befits a patch release, the focus is on bugs, breakages, and performance issues. Users with large tables of points will want to priorize this patch, for substantial (~50%) disk space savings.

http://download.osgeo.org/postgis/source/postgis-2.1.6.tar.gz

Enhancements
•         #3000, Ensure edge splitting and healing algorithms use indexes
•         #3048, Speed up geometry simplification (J.Santana @ CartoDB)
•         #3050, Speep up geometry type reading (J.Santana @ CartoDB)

Bug Fixes
•         #2941, allow geography columns with SRID other than 4326
•         #3069, small objects getting inappropriately fluffed up w/ boxes
•         #3068, Have postgis_typmod_dims return NULL for unconstrained dims
•         #3061, Allow duplicate points in JSON, GML, GML ST_GeomFrom* functions
•         #3058, Fix ND-GiST picksplit method to split on the best plane
•         #3052, Make operators <-> and <#> available for PostgreSQL < 9.1
•         #3045, Fix dimensionality confusion in &&& operator
•         #3016, Allow unregistering layers of corrupted topologies
•         #3015, Avoid exceptions from TopologySummary
•         #3020, ST_AddBand out-db bug where height using width value
•         #3031, Allow restore of Geometry(Point) tables dumped with empties in them

View all closed tickets<http://trac.osgeo.org/postgis/query?status=closed&groupdesc=1&group=priority&milestone=PostGIS+2.1.6&order=priority>.

--
Paul Ramsey
http://cleverelephant.ca
http://postgis.net

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