On Sat, Oct 13, 2012 at 12:49 PM, Joshua Berkus <j...@agliodbs.com> wrote: > > So, problem #1 is coming up with a mathematical formula. My initial target > values are in terms of # of rows in the table vs. # of writes before analyze > is triggered: > > 1 : 3 > 10 : 5 > 100 : 10 > 1000 : 100 > 100000 : 2000 > 1000000 : 5000 > 10000000 : 25000 > 100000000 : 100000 > > .... etc. So problem #1 is a mathematical formula which gives this kind of > curve. I've tried some solution-seeking software, but I don't know how to > use it well enough to get something useful.
That is close to a power law, where best fit is about "threshold = 1.5 * (rows ** 0.6)" rows yours powerfit 1.00E+00 3.00E+00 1.50E+00 1.00E+01 5.00E+00 5.97E+00 1.00E+02 1.00E+01 2.38E+01 1.00E+03 1.00E+02 9.46E+01 1.00E+05 2.00E+03 1.50E+03 1.00E+06 5.00E+03 5.97E+03 1.00E+07 2.50E+04 2.38E+04 1.00E+08 1.00E+05 9.46E+04 If you want something more natural, reduce the exponent from 0.6 to 0.5 so it becomes the square root. I have no opinion on the suitability of this, I'm just crunching the numbers for you. Cheers, Jeff -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
