Hi Andrei,
> On 4/3/24 01:22, Tomas Vondra wrote:
>> Cool! There's obviously no chance to get this into v18, and I have stuff
>> to do in this CF. But I'll take a look after that.
> I'm looking at your patch now - an excellent start to an eagerly awaited
> feature!
> A couple of questions:
> 1. I didn't find the implementation of strategy 'c' - estimation by the
> number of distinct values. Do you forget it?
What do you mean the "strategy 'c'"?
> 2. Can we add a clauselist selectivity hook into the core (something
> similar the code in attachment)? It can allow the development and
> testing of multicolumn join estimations without patching the core.
The idea LGTM. But do you want
+ if (clauselist_selectivity_hook)
+ s1 = clauselist_selectivity_hook(root, clauses, varRelid, jointype,
+
rather than
+ if (clauselist_selectivity_hook)
+ *return* clauselist_selectivity_hook(root, clauses, ..)
?
--
Best Regards
Andy Fan
