What is the point of that, and if there is a point, why is it nowhere
mentioned in pgbench.sgml?
The attached patch simplifies the code by erroring on cache overflow,
instead of the LRU replacement strategy and unhelpful final report.
The above lines are removed.
Eh? Do I understand correctly that pgbench might start failing after
some random amount of time, instead of reporting the overflow at the
end?
Indeed, that what this patch would induce, although very probably under a
*short* random amount of time.
I'm not sure that's really an improvement ...
Depends. If the cache is full it means repeating the possibly expensive
constant computations, which looks like a very bad idea for the user
anyway.
Why is the cache fixed-size at all?
The cache can diverge and the search is linear, so it does not seem a good
idea to keep it for very long:
\set size random(100000, 1000000)
\set i random_zipfian(1, :size, ...)
The implementation only makes some sense if there are very few values
(param & size pairs with param < 1) used in the whole script.
Tom is complaining of over engineering, and he has a point, so I'm trying
to simplify (eg dropping LRU and erroring) for cases where the feature is
not really appropriate anyway.
--
Fabien.
