Hi, Draft version of the patch attached (it is based on Simon's) I would be happier if we could make that #define into GUC (just in case), although I do understand the effort to reduce the number of various knobs (as their high count causes their own complexity).
-Jakub Wartak. On Mon, Nov 21, 2022 at 4:35 PM Robert Haas <robertmh...@gmail.com> wrote: > > On Mon, Nov 21, 2022 at 10:32 AM Tom Lane <t...@sss.pgh.pa.us> wrote: > > Robert Haas <robertmh...@gmail.com> writes: > > > Is there any reason to tie this into page costs? I'd be more inclined > > > to just make it a hard limit on the number of pages. I think that > > > would be more predictable and less prone to surprising (bad) behavior. > > > > Agreed, a simple limit of N pages fetched seems appropriate. > > > > > And to be honest I would be inclined to make it quite a small number. > > > Perhaps 5 or 10. Is there a good argument for going any higher? > > > > Sure: people are not complaining until it gets into the thousands. > > And you have to remember that the entire mechanism exists only > > because of user complaints about inaccurate estimates. We shouldn't > > be too eager to resurrect that problem. > > > > I'd be happy with a limit of 100 pages. > > OK. > > -- > Robert Haas > EDB: http://www.enterprisedb.com
0001-Damage-control-for-planner-s-get_actual_variable_end.patch
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