On 08/03/2016 08:47 PM, Andrey Borodin wrote:
1. Currenlty overflow is carried every 9999 addition. I suggest that it is possibe to do it only every (INT32_MAX - INT32_MAX / NBASE) / (NBASE - 1) addition. Please note that with this overflow count it will be neccesary to check whether two finishing carrings are required.
I left it at (NBASE -1), but added a comment on that. I couldn't measure any performance difference between that and a larger interval, so it didn't seem worthwhile. The code wouldn't be much more complicated, but the math required to explain what the safe maximum is, would be :-).
2. Aggregates and numeric regression tests do not containt any test case covering overflows. I recommend adding sum with numer 1 000 000 of 99 999 999 values. May be you will come up with more clever overflow testing.
Hmm. Added a couple of simple SUM() queries to the regression tests, so that we have at least some test coverage of the overflows. But nothing very clever.
Looking closer, I don't think this implementation is actually dependent on NBASE being 10000. So I removed the comment changes that suggested so.
I did some more minor comment fixes, and committed. Thanks for the review! - Heikki -- Sent via pgsql-hackers mailing list (email@example.com) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers