>> The existing cost estimation >> code effectively assumes that they're perfectly uniformly distributed; >> which is a good average-case assumption but can be horribly wrong in >> the worst case.
Sorry, just an outsider jumping in with a quick comment. Every year or two the core count goes up. Can/should/does postgres ever attempt two strategies in parallel, in cases where strategy A is generally good but strategy B prevents bad worst case behaviour? Kind of like a Schrödinger's Cat approach to scheduling. What problems would it raise? Graeme. -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
