Message-ID: <4B6B153D.9030200@emolecules.com>
Date: Thu, 04 Feb 2010 10:43:09 -0800
From: Craig James <craig_james@emolecules.com>
User-Agent: Thunderbird 2.0.0.23 (X11/20090817)
MIME-Version: 1.0
To: Tory M Blue <tmblue@gmail.com>
CC: pgsql-performance@postgresql.org
Subject: Re: bigint integers up to 19 digits.
References: <8a547c841002041015o57d533fdg7237c50dea7a9278@mail.gmail.com>
In-Reply-To: <8a547c841002041015o57d533fdg7237c50dea7a9278@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit

Tory M Blue wrote:
> I have a column that is a bigint that needs to store integers up to 19
> digits long. For the most part this works but we sometimes have
> numbers that are greater than 9223372036854775807.
> ...
> I was thinking of changing this to a real or double precision field,
> but read in the docs that the value stored is not always the value
> inserted...

They're actually less precise than the same size of integer.  Real/double datatypes trade more range for less precision in the same number of bytes.

> My number will always be 19 digits long and always an integer.
> I looked into the numeric data type, but the docs say that it can be slow.

If it's *always* going to be 19 digits, couldn't you make it a text or char field?  You didn't say if this is really a number.  Do you do arithmetic with it? Sort it numerically?  Or is it just a long identifier that happens to only used digits?

Craig James