From: | "Thomas G(dot) Lockhart" <lockhart(at)alumni(dot)caltech(dot)edu> |
---|---|
To: | Bruce Momjian <maillist(at)candle(dot)pha(dot)pa(dot)us> |
Cc: | hackers(at)postgresql(dot)org |
Subject: | Re: [HACKERS] varchar/char size |
Date: | 1998-01-08 03:20:14 |
Message-ID: | 34B445ED.9F225EA2@alumni.caltech.edu |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
Bruce Momjian wrote:
> >
> > > Does someone want to remind me why we allocate the full size for char()
> > > and varchar(), when we really can just allocate the size of the given
> > > string?
> > > I relize char() has to be padded, but why varchar()?
> >
> > > In my experience, char() is full size as defined by create, and
> > > varchar() is the the size of the actual data in the field, like text,
> > > but with a pre-defined limit.
> >
> > Well, in many relational databases access can be optimized by having
> > fixed-length tuple storage structures. Also, it allows re-use of deleted
> > space in storage pages. It may be that neither of these points have any
> > bearing on Postgres, and never will, but unless that clearly the case then
> > I would be inclined to keep the storage scheme as it is currently.
>
> With Ingres and Informix char() is fixed size, while varchar() is
> VARiable size.
Go for it. Let me know if I can help with testing or anything...
- Tom
From | Date | Subject | |
---|---|---|---|
Next Message | Bruce Momjian | 1998-01-08 03:24:21 | Re: [HACKERS] varchar/char size |
Previous Message | Bruce Momjian | 1998-01-08 03:17:50 | Re: [HACKERS] varchar/char size |