On 10/11/2012 05:07 PM, Vineet Deodhar wrote:
On Thu, Oct 11, 2012 at 1:12 PM, Craig Ringer <ringerc@xxxxxxxxxxxxx <mailto:ringerc@xxxxxxxxxxxxx>> wrote: The difference between SMALLINT and BOOLEAN (or TINYINT if Pg supported it) is 1 byte per column. If you had 30 smallint columns and quite a few million rows it might start making a difference, but it's *really* not worth obsessing about. Unless you have high-column-count tables that contain nothing but lots of integers of range 0-255 there's no point caring. -- Craig Ringer To give an example, I have tables for storing master records (year master, security master, etc.) for which pkid TINYINT is just sufficient. These pkid's are used as fk constraints in tables for storing business transactions. The no. of rows in business transactions tables is in millions. Here, I NEED to worry about the storage space occupied by the pkid fields.
AFAIK in most situations alignment requirements will mean you won't gain any space in those situations anyway.
I would be truly amazed if you saw more than something like a 1% difference in size due to this; it'll be *massively* outweighed by all the other differences. You're optimising prematurely. See if it's a problem in practice, and if it is look into using a custom data type (warning: lots of work) or some other approach.
-- Craig Ringer -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
