Re: reducing NUMERIC size for 9.1

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Robert Haas <robertmhaas@gmail.com>
Cc: pgsql-hackers@postgresql.org
Date: 2010-07-30T18:08:19Z
Lists: pgsql-hackers
Robert Haas <robertmhaas@gmail.com> writes:
> ....  Maybe something like this,
> obviously with a suitable comment which I haven't written yet:

>     numeric_digits = (precision + 6) / 4;
>     return (numeric_digits * sizeof(int16)) + NUMERIC_HDRSZ;

This is OK for the base-10K case, but there's still code in there
for the base-10 and base-100 cases.  Can you express this logic in
terms of DEC_DIGITS and sizeof(NumericDigit) ?  I think you might
find it was actually clearer that way, cf Polya.

			regards, tom lane