Re: Suggested TODO: allow ALTERing of typemods without heap/index rebuild - Mailing list pgsql-hackers

From Jeff Davis
Subject Re: Suggested TODO: allow ALTERing of typemods without heap/index rebuild
Date
Msg-id 1243893525.12209.51.camel@monkey-cat.sm.truviso.com
Whole thread Raw
In response to Re: Suggested TODO: allow ALTERing of typemods without heap/index rebuild  (Josh Berkus <josh@agliodbs.com>)
Responses Re: Suggested TODO: allow ALTERing of typemods without heap/index rebuild  (Josh Berkus <josh@agliodbs.com>)
List pgsql-hackers
On Mon, 2009-06-01 at 14:39 -0700, Josh Berkus wrote:
> Note that this doesn't deal with the special case of VARCHAR-->TEXT, but 
> just with changing typemods.  Are there other cases of data *type* 
> conversions where no check or rebuild is required?  Otherwise we might 
> just special case VARCHAR-->TEXT.

I observe that the casts (VARCHAR -> TEXT and TEXT -> VARCHAR) are
marked WITHOUT FUNCTION. If that's the case, can't we use that to say
that no heap rebuild is required? Perhaps we'll need to combine this
with the typmod checks to see if we need to check the heap. 

Regards,Jeff Davis



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