Re: column size and storage efficiency

--- On Tue, 11/25/08, Sean Davis <sdavis2(at)mail(dot)nih(dot)gov> wrote:

> > My inclination when creating tables is to create
> columns using
> > varchar-sizes in increments of 10 or 5 but I suspect
> there must be
> > more-efficient sizes, specifically, values like 16,
> 32, 64 minus
> > header-bits.
> >
> > - Is this true? Does it really have much impact on
> storage?
> > - How many bits are the headers?
> > - How does TOAST factor in?
>
>
> Believe it or not, specifying the varchar size has no
> impact on storage
> size. So, a varchar and a varchar(2) if both have two
> characters take the
> same storage space.

After thinking about it more, there can't be a direct relationship between number-of-characters and number-of-bits but what I meant was, if varchar(14) fills a block of storage, does varchar(15) use 2 blocks? Does it use twice the storage?

Bruce