All,
I know I've skipped multiple releases so this is a difficult question to answer, but should I expect the Dec2016-SP5 version of MonetDB to be faster than/equal to the Jul2015-SP4 version? I have a parallel set of servers (on the same box, 24 cores 192GB ram, listening to different ports) operating on identical data sets, and the Dec2016 version is slower than the Jul2015 version (~15-20%). My queries are basic joins between two tables with grouping. I have top running on the same box, and I can see that the Jul2015 server uses all 24 cores, but the Dec2016 server barely cracks 2-3.
The MAL plans obtained by explain are totally different (which partly explains the cores being utilized because I can see blocks of 24 commands) and the length of the Dec2016 one is a fraction of the Jul2015 version.
I guess the older version was inefficiently using all 24 cores, but the new version efficiently uses a smaller set of cores??
Thanks, Dave