Sometimes my PostGIS database creates a extended_geometry_columns table. After some search i've not found what is the use of this table.

I'm using PostgreSQL 8.4 and PostGIS 1.3.3

This is the definition of the table

CREATE TABLE extended_geometry_columns (
    f_table_schema character varying(265) NOT NULL,
    f_table_name character varying(256) NOT NULL,
    x_min double precision,
    y_min double precision,
    x_max double precision,
    y_max double precision,
    CONSTRAINT extended_geometry_columns_pkey PRIMARY KEY (f_table_schema, f_table_name)


AFAIK the only tools that are connecting to the database are pgadmin3/psql, gvSIG, and some custom python scripts (that i'm sure not create the table).


  • I've been using PostGIS forever since 0.8, and I don't recall there ever being an extended_geometry_columns. What columns does it have in it? You don't have other software that writes to the db like ArcGIS or MapInfo. I recall those two create additional tables though I think they created them in their own special schema (sde, mapinfo). – LR1234567 Nov 14 '11 at 23:04
  • That is kind of weird. What is especially strange about this table you have is that there is no geometry column in it and a table could have more than one geometry column. So the assumption it is making about the x,y min/max I have no idea what name of column it would be assuming. Is it possible that it is a gvSig plugin (not gvSig core) – LR1234567 Nov 15 '11 at 17:58
  • I also grep the not official plugins that i'm using. I remove the table and i try to catch the moment when is created. – Francisco Puga Nov 17 '11 at 9:51

Whatever it is, it's not PostGIS creating it. I've just downloaded the source for 1.3.3 (you really should be using a more up-to-date version...)

Unzipped it:

tar xzf postgis-1.3.3.tar.gz
cd postgis-1.3.3

and grepped for _geometry_column:

grep _geometry_column -iR *

And apart from a few references to the function fix_geometry_columns() and probe_geometry_columns() nothing has come up.

What other software are you using on this database? Like you, I found Google only turned up links to this question, so it may be that if you are using closed-source software like ArcGIS, it is something that software adds to speed up some process or other.

  • I grep the gvSIG code and i not find reference to that table... I'm not sure what app can be creating it. Thanks – Francisco Puga Nov 15 '11 at 9:10

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