Re: List of "binary-compatible" data types

Andres Freund <andres@2ndquadrant.com>

From: Andres Freund <andres@2ndquadrant.com>
To: Josh Berkus <josh@agliodbs.com>
Cc: pgsql-hackers@postgresql.org, Noah Misch <noah@leadboat.com>
Date: 2013-11-05T19:20:12Z
Lists: pgsql-hackers
On 2013-11-05 11:15:29 -0800, Josh Berkus wrote:
> Noah,
> 
> > That's all true, but the system has no concept like "this cast validates the
> > data, never changing it".  We would first need to add metadata supporting such
> > a concept.  On the other hand, "create cast (json as text) without function;"
> > leans only on concepts the system already knows.
> > 
> 
> Yeah, I'm thinking it might be worth coming up with a solution for that
> specific case.  As users upgrade from 9.0 and 9.1 to 9.3, they're going
> to want to convert their text columns containing JSON to columns of the
> JSON type, and are going to be surprised how painful that is.

There's zap chance of doing anything for 9.3, this would require quite a
bit of code in tablecmds.c and that surely isn't going to happen in the
backbranches.

Greetings,

Andres Freund

-- 
 Andres Freund	                   http://www.2ndQuadrant.com/
 PostgreSQL Development, 24x7 Support, Training & Services


Commits

  1. Avoid some table rewrites for ALTER TABLE .. SET DATA TYPE timestamp.

  2. Disable transforms that replaced AT TIME ZONE with RelabelType.

  3. Add transform functions for AT TIME ZONE.