NUMERIC size - Mailing list pgsql-docs

From Fujii Masao
Subject NUMERIC size
Date
Msg-id CAHGQGwGupGaNmQQHHhm783j9vMiNYtPFZaE0eKwsCLGwMU2x+Q@mail.gmail.com
Whole thread Raw
Responses Re: NUMERIC size  (Robert Haas <robertmhaas@gmail.com>)
List pgsql-docs
Hi,

> Numeric values are physically stored without any extra leading or
> trailing zeroes. Thus, the declared precision and scale of a column
> are maximums, not fixed allocations. (In this sense the numeric type
> is more akin to varchar(n) than to char(n).) The actual storage
> requirement is two bytes for each group of four decimal digits,
> plus five to eight bytes overhead.

The last sentence of the above seems not to be correct. Because,
thanks to the reduction of NUMERIC size (committed in 9.1), its header
size is three, five or eight for now. Attached patch fixes this.

Regards,

--
Fujii Masao
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center

Attachment

pgsql-docs by date:

Previous
From: Robert Haas
Date:
Subject: Re: Update documentation wrt visibility map/index-only scans
Next
From: Tom Lane
Date:
Subject: Re: Cannot build docs on Ubuntu 10.04?