Andres Freund <and...@2ndquadrant.com> writes: > On Sunday, September 30, 2012 10:33:28 PM Tom Lane wrote: >> I'm still pretty desperately unhappy with your insistence on circularly >> linked dlists. Not only does that make initialization problematic, >> but now it's not even consistent with slists.
> We literally have tens of thousands list manipulation a second if the server > is > busy. Tens of thousands, with maybe 1ns extra per call, adds up to what? > I am really sorry for being stubborn here, but I changed to circular lists > after profiling and finding that pipeline stalls & misprediced branches where > the major thing I could change. Not sure how we can resolv this :( I'm going to be stubborn too. I think you're allowing very small micro-optimization arguments to contort the design of a fundamental data structure, in a way that makes it harder to use. That's not a tradeoff I like. Especially when the micro-optimization isn't even uniformly a win. I remain of the opinion that the extra cycles spent on iteration (which are real despite your denials) will outweigh any savings in list alteration in many use-cases. regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers