Re: reserving space in a rec for future update

On Nov 14, 2007 9:28 AM, Gauthier, Dave <dave.gauthier@intel.com> wrote:
>
> Hi:
>
> I have a situation where I will be inserting thousands of records into a
> table but leaving 2 of it's columns null.  Later on, I will be updating most
> of those records and putting real values in  place of those 2 nulls. As for
> the ones that do not get updated, I want to leave them null.   My concern
> has to do with record fragmentation at the time of update because there's no
> room to "expand" them to accept the non-null data.  (BTW, the columns are
> floating point).

I don't think you really understand how PostgreSQL storage works.
every update is the exact same as a delete / insert in terms of
storage.  So, you're worrying about a problem that doesn't exist.
Read up

Read up on it here:  http://www.postgresql.org/docs/8.2/static/mvcc.html