Hi John, About the perf, i'm trying to understand what could justify such a difference (my ~90k queries test jumped from 20s to 120s while we should be handling the same number of bit vectors). So far, it seems that ~70% of the time is spent in ibis::bitvector::do_cnt(). I'll try the sort trick to see how it affects performance. I tend to be carefull with profiler results and favor your knowledge of the codebase.
Thanks, -----Original Message----- From: K. John Wu [mailto:[email protected]] Sent: Thursday, March 15, 2012 4:56 PM To: Dominique Prunier Cc: FastBit Users Subject: Re: [FastBit-users] PATCH: new CS_PATTERN_MATCH define added to match LIKE patterns case-sensitively and perform specific optimizations Hi, Dominique, Regarding the test cases, whenever you are ready to share is fine. Regarding the performance, my guess is that the bit vectors are more spread out in the new corrected approach. When the bit vectors are spread out, FastBit needs to read more bytes in order to get them out. If this is indeed the case, the thing to do might to sort the values before returning them from ibis::dictionary::patternSearch with something like std::sort(matches.begin(), matches.end()); John On 3/15/12 12:24 PM, Dominique Prunier wrote: > Hey John, > > The problem is that right know, my test suite mainly tests the > import and not so much the queries (i have maybe 10-20 test cases > that actually evaluates queries). It has been basically modeled > after our existing test suite for MySQL/Oracle and is supposed to > prove that the imported data is equivalent to our source. > > My next step is to do a micro testing framework to test queries. I > have a very simplistic example which only uses CATEGORY and LONG > (the only two types that we're using), but it is not convenient > enough to use. > > Be sure that i'll post in the group if i have something good enough > to be shared :) > > Regarding the bug i found yesterday, surprisingly enough, fixing it > changed the performance quite significantly. I'm still not sure why > (the number of selected bitmap was the same), but i'll try to > investigate a bit further. > > Thanks, > _______________________________________________ FastBit-users mailing list [email protected] https://hpcrdm.lbl.gov/cgi-bin/mailman/listinfo/fastbit-users
