Populate_Geometry_Columns is a function introduced in PostGIS 1.4. So yes you are right the probe_geometry_columns is a lighter weight that doesn't look at views and just looks at the constraints of tables. Speaking of this. In PostGIS 2.0, the plan is to use typmod support for geometry (like what we currently have for geography) as well and make geometry_columns a view instead of a table as it is now There are a couple of issues with this: 1) Existing data does not use typmod so there is a portability question of if people want to use the new geometry_columns should they be forced to convert their data to typmod. (I say no). 2) Exotic uses of geometry_columns that inspecting the system catalogs will not handle (e.g. views and other reasons for manual registration) Anyrate the thread is outlined here: http://trac.osgeo.org/postgis/ticket/944 I think the typmod is a done deal -- we are all in agreement we want this. What is not a done deal is how best to formulate geometry_columns view. I proposed a hybrid -- where part of the geometry_columns view reads from the system catalog and the other part reads from a static table (basically old geometry_columns table would be renamed and populate and so forth would be changed to add to this table). Anyway I admit the hybrid is less than pretty, but the alternatives look even more ugly to me from a migration standpoint and supporting more exotic uses. We'd be interested in hearing how people feel about these approaches and any other ideas as to how we can fuse the old with the new. Thanks, Regina http://www.postgis.us
_____ From: postgis-users-boun...@postgis.refractions.net [mailto:postgis-users-boun...@postgis.refractions.net] On Behalf Of Ben Madin Sent: Wednesday, May 18, 2011 9:27 PM To: pcr...@pcreso.com; PostGIS Users Discussion Subject: Re: [postgis-users] how to keep geometry_columns in sync with tables and views G'day Brent, I'm forever creating tables as subsets of existing tables so it is a truly useful function, however, I've suffered the same concerns - perhaps it is worth pursuing the name being changed? I've also never really understood the distinction between the populate_ and the probe_ functions? the probe_ one appears to be a 'lite' version, but it may have some other purpose that I don't understand? cheers Ben On 19/05/2011, at 9:02 AM, pcr...@pcreso.com wrote: I foubd this an unfortunately ambiguous name. it doesn't populate geometry columns so much as update the geometry_columns table. But irrespective of the name, it is nice to have :-) Cheers Brent Wood --- On Thu, 5/19/11, Ben Madin <li...@remoteinformation.com.au> wrote: From: Ben Madin <li...@remoteinformation.com.au> Subject: Re: [postgis-users] how to keep geometry_columns in sync with tables and views To: "PostGIS Users Discussion" <postgis-users@postgis.refractions.net> Date: Thursday, May 19, 2011, 12:50 PM Ge, Try SELECT Populate_Geometry_Columns(); http://postgis.refractions.net/docs/Populate_Geometry_Columns.html which promises to truncate the geometry columns table first, then rebuild it. cheers Ben On 18/05/2011, at 8:05 PM, G. van Es wrote: Hi Edward, This will not work because this function doesn't do anything with views. Also stale records aren't removed. Ge --- On Wed, 5/18/11, Edward Mac Gillavry <emacgilla...@hotmail.com <x-msg://119/mc/compose?to=emacgilla...@hotmail.com> > wrote: From: Edward Mac Gillavry <emacgilla...@hotmail.com <x-msg://119/mc/compose?to=emacgilla...@hotmail.com> > Subject: Re: [postgis-users] how to keep geometry_columns in sync with tables and views To: postgis-users@postgis.refractions.net <x-msg://119/mc/compose?to=postgis-users@postgis.refractions.net> Date: Wednesday, May 18, 2011, 4:57 AM Hi Ge, You may want to check Probe_Geometry_Columns (http://postgis.refractions.net/docs/Probe_Geometry_Columns.html). Kind regards, Edward _____ Date: Wed, 18 May 2011 04:38:51 -0700 From: gves2...@yahoo.com <x-msg://119/mc/compose?to=gves2...@yahoo.com> To: postgis-users@postgis.refractions.net <x-msg://119/mc/compose?to=postgis-users@postgis.refractions.net> Subject: [postgis-users] how to keep geometry_columns in sync with tables and views Hi All, We have a lot of tables and views updated, or better said, replaced on a daily basis. We have seen that under certain conditions (which are unclear) entries of the geometry_columns table are removed. So a mismatch occurs so now and then resulting in showing either no data or being very slow when an application has to do a table scan to obtain the geometry type. What I like to have is a procedure which checks all tables and views against the geometry_columns table and makes if necessary the right corrections. Before inventing the wheel again, does anyone know if this procedure already exist or knows perhaps another/better way to achieve this? Thanks in advance, Ge _______________________________________________ postgis-users mailing list postgis-users@postgis.refractions.net <x-msg://119/mc/compose?to=postgis-users@postgis.refractions.net> http://postgis.refractions.net/mailman/listinfo/postgis-users -----Inline Attachment Follows----- _______________________________________________ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users _______________________________________________ postgis-users mailing list postgis-users@postgis.refractions.net <x-msg://119/mc/compose?to=postgis-users@postgis.refractions.net> http://postgis.refractions.net/mailman/listinfo/postgis-users -----Inline Attachment Follows----- _______________________________________________ postgis-users mailing list postgis-users@postgis.refractions.net <x-msg://119/mc/compose?to=postgis-users@postgis.refractions.net> http://postgis.refractions.net/mailman/listinfo/postgis-users _______________________________________________ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
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