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: | PostgreSQL-development <hackers(at)postgresql(dot)org> |
Subject: | Re: [HACKERS] varchar/char size |
Date: | 1998-01-08 03:07:13 |
Message-ID: | 34B442E1.E4C6D924@alumni.caltech.edu |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
> 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.
- Tom
From | Date | Subject | |
---|---|---|---|
Next Message | Bruce Momjian | 1998-01-08 03:17:50 | Re: [HACKERS] varchar/char size |
Previous Message | Bruce Momjian | 1998-01-08 03:03:22 | rollback varchar change |