[postgis-users] [postgis-devel] how to keep geometry_columns in sync wit tablesand views (and new PostGIS 2.0 plans)

Paragon Corporation lr at pcorp.us
Sun May 22 09:19:41 PDT 2011


Steve,
* Paragon Corporation (lr at pcorp.us) wrote:
> I would almost go with forcing everyone to change their existing 
> tables to typmod if they want to reap the benefits of PostGIS 2.0, but 
> most of my clients will not go to 2.0 then.

> What I havn't heard yet is any explanation or description of *why* they
wouldn't want to move to 2.0 if it only supported the typmod approach..?

See my comment in the trac item - (short answer there are some use cases
that just can't be implemented with typmod)
http://trac.osgeo.org/postgis/ticket/944#comment:22

> We could try Mark's idea of hacking the catalog tables to 
> automagically convert table constraints to typmod but that all sounds
pretty scary to me.

> The upgrade question should not be terribly difficult to solve by just
using the current geometry_columns table to help with the generation of the
new tables...?
New tables -- oh no, you'd have to do an alter (or as Mark wants directly
update the catalogs)  -- imagine the nightmare if you have foreign key
constraints and what not having to create new tables.
I have no tables to test with since we don't have typmod, but once Paul gets
typmod in there (HINT HINT), I can test with fairly large tables to see how
painful doing an alter and dropping constraints would be.

> Especially with my special
> Inheritcance case -- I can just see that failing miserably and 
> screwing up my tables.

> Can you provide more insight on this..?  I'm not familiar with your
'special inheritance case'..
See trac comment.

Thanks,
Regina
http://www.postgis.us






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