[postgis-devel] geographystyle feature request (external textual representation)

[Malek,Christophe [CMC]]

Hi strk,

I was using the same terminology as from the "CREATE TYPE"
documentation:
http://www.postgresql.org/docs/9.5/static/sql-createtype.html where they
refer to "external textual representation" and "external binary
representation" vs "internal representation". It would indeed make sense
that these most likely refer to the "canonical text" and "canonical
binary" forms but they don't appear to use the same terminology in
either document.
http://www.postgresql.org/docs/9.4/static/app-pgdump.html only talks
about "plain", and "custom" formats.

RE:
If you do:
 SET geometry_output_style WKT
You don't want a subsequent pg_dump call to get the WKT representation.

Perhaps I do want the WKT representation. More so if I ask for a text
dump instead of a binary one. Ultimately I think it should be the users'
choice depending on what style they select. Please refer to my e-mail to
Mark for details of why somebody might or might not want to do this.

RE: I'm not the one feeling a need for this feature :)
lol. Indeed. Truthfully, it is not that urgent for me either. I was
mainly hoping to get the ball rolling in case somebody else finds it a
good idea and can make my life easier in the future.

Regarding the appropriateness of WKT, please see my e-mail to Mark.

Cheers,
Chris

Chris Malek
christophe.malek at ec.gc.ca
Data Assimilation Informatics
Canadian Meteorological Centre
2121 Trans Canada Highway
Dorval, Quebec
H9P 1J3

-----Original Message-----
From: postgis-devel-bounces at lists.osgeo.org
[mailto:postgis-devel-bounces at lists.osgeo.org] On Behalf Of Sandro
Santilli
Sent: 09 September, 2015 15:47
To: PostGIS Development Discussion
Subject: Re: [postgis-devel] geographystyle feature request (external
textual representation)

On Wed, Sep 09, 2015 at 03:06:12PM -0400, Malek,Christophe [CMC] wrote:
> Hi strk,
> 
> I'm not sure how pg_dump decides which representation to use in its 
> dumps. I would assume it uses the "external textual representation" 
> when dumping to text (pg_dump -Fp) and uses the "external binary 
> representation" when dumping to binary (pg_dump -Fc) but it isn't 
> entirely clear from the documentation if this is true.

I believe it is, they are called "canonical text" and "canonical binary"
representations.

> I don't think I understand how GUC lifetime relates to what should be 
> output in a dump. Perhaps you could elaborate on the use case?

If you do:

 SET geometry_output_style WKT

You don't want a subsequent pg_dump call to get the WKT representation.

> You can wait for a patch from me but you may be waiting a very very 
> long time ;)

I'm not the one feeling a need for this feature :)

Generally, even WKT is not appropriate for a user, unless the geometry
is really just a point. Text representation may be huge, I'd rather
check with the client if there's a way to tweak how some values are
displayed, if supported (like I think there might be a map widget plugin
in pgadmin?).

--strk;
_______________________________________________
postgis-devel mailing list
postgis-devel at lists.osgeo.org
http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-devel