On 2014-08-26 20:44:32 -0500, Jim Nasby wrote: > These results look very encouraging, especially thinking about the > cache impact.
Yep. I've seen PrivateRefCount array accesses prominently in the source of cache misses in big servers. > It occurs to me that it'd also be nice to have some > stats available on how this is performing; perhaps a dtrace probe for > whenever we overflow to the hash table, and one that shows maximum > usage for a statement? (Presumably that's not much extra code or > overhead...) I don't use dtrace, so *I* won't do that. Personally I just dynamically add probes using "perf probe" when I need to track something like this. I don't see how you could track maximum usage without more compliations/slowdowns than warranted. Greetings, Andres Freund -- Andres Freund http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers