Re: Idea - fallback mode for psql backslash commands using information_schema - Mailing list pgsql-hackers

From Bruce Momjian
Subject Re: Idea - fallback mode for psql backslash commands using information_schema
Date
Msg-id 200812292102.mBTL24X23106@momjian.us
Whole thread Raw
In response to Idea - fallback mode for psql backslash commands using information_schema  ("Dawid Kuroczko" <qnex42@gmail.com>)
List pgsql-hackers
Dawid Kuroczko wrote:
> Hi!
> 
> I think I've got a nice TODO item for psql client:
> 
> When a client connects to a database which has unknown (newer)
> version it might be advisable to 'fallback' some commands to use
> INFORMATION_SCHEMA instead of system catalogs.
> 
> 
> For instance when connected to 8.4dev server using 8.3 client,
> after issuing \d foo_table you get:
> ERROR:  column "reltriggers" does not exist
> LINE1: SELECT relhasindex, relkind, relchecks, reltriggers, relhasr....
> 
> Of course the information_schema will probably be less efficient
> and won't have PostgreSQL-specific items like 'Has OIDs', but
> the user experience should be better.
> 
> My question is: does it look like a good TODO item? :)

That seems like duplicate effort.  The clearer solution would just be to
use information_scema where possible for all psql backslash commands so
you don't have to maintain two versions.  I think the problem is that
lots of information we need is not in the information schema.

--  Bruce Momjian  <bruce@momjian.us>        http://momjian.us EnterpriseDB
http://enterprisedb.com
 + If your life is a hard drive, Christ can be your backup. +


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