Re: bug in zcatalog queryplan causing very slow first query after startup
Leonardo Rochael Almeida <[email protected]>
| Newsgroups | gmane.comp.web.zope.plone.devel |
|---|---|
| Message-ID | <CAMxX_oOvgKAWBcko8NH=_28w1tbk9k1wiRZsKP=WRF64j=W-Cw@mail.gmail.com> |
Hi Hanno, Awesome explanation. Just a small correction: On Thu, Oct 17, 2013 at 7:38 PM, Hanno Schlichting <[email protected]>wrote: > > [...] One could maintain additional BTrees.Length counters for all > BTrees as part of the normal insert/delete work, but this would increase > conflict errors and thus quickly have a negative impact. > It's likely true that it could increase overread due to conflicts in the case where two transactions would only affect different buckets of the same BTree. But it would not necessarily raise conflict errors or cause retries, as BTrees.Length contain conflict resolution code [1] that runs on the ZEO side if it has access to the BTrees.Length class. [1] https://github.com/zopefoundation/BTrees/blob/master/BTrees/Length.py#L48-L49 ------------------------------------------------------------------------------ October Webinars: Code for Performance Free Intel webinars can help you accelerate application performance. Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most from the latest Intel processors and coprocessors. See abstracts and register > http://pubads.g.doubleclick.net/gampad/clk?id=60135031&iu=/4140/ostg.clktrk _______________________________________________ Plone-developers mailing list Plone-developers-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org https://lists.sourceforge.net/lists/listinfo/plone-developers