Hello Fabien, > > I think that this method should be used for a>1, and the other very rough one > can be kept for parameter a in [0, 1), a case which does not make much sense > to a mathematician as it diverges if unbounded.
Now “a” does not have upper bound, that’s why on using iterative algorithm with a >= 10000 program will stuck on infinite loop because of following line of code: double b = pow(2.0, s - 1.0); Because after overflow “b” becomes “+Inf”. So should upper bound for “a" be set? Should I mention in docs that there are two algorithms are used depending on values of a(s/theta)? In attaching patch, I have added computeIterativeZipfian method and it’s usage in getZipfianRand. Is it better to move code of computing via cache to new method, so that getZipfianRand will contain only 2 computeXXXZipfian method calls?
pgbench-zipf-06v.patch
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— Thanks and Regards, Alik Khilazhev Postgres Professional: http://www.postgrespro.com The Russian Postgres Company
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