Re: reducing NUMERIC size for 9.1

2010/7/16 Brendan Jurd <direvus(at)gmail(dot)com>:
> On 16 July 2010 03:47, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
>> You might also look at testing with pg_column_size().
>>
>
> pg_column_size() did return the results I was expecting.
> pg_column_size(0::numeric) is 8 bytes on 8.4 and it's 6 bytes on HEAD
> with your patch.
>
> However, even with 1 million rows of 0::numeric in my test table,
> there was no difference at all in the on-disk relation size (36290560
> with 36249600 in the table and 32768 in the fsm).
>
> At this scale we should be seeing around 2 million bytes saved, but
> instead the tables are identical.  Is there some kind of disconnect in
> how the new short numeric is making it to the disk, or perhaps another
> effect interfering with my test?

What about large ARRAY of numeric type? Once upon a time I develop
tinyint for myself, the array size could get reduced.

Regards,

--
Hitoshi Harada