On Sun, Mar 15, 2020 at 1:08 PM Tomas Vondra <tomas.von...@2ndquadrant.com> wrote: > On Sat, Mar 14, 2020 at 05:56:10PM +0100, Tomas Vondra wrote: > >Attached is a patch series rebased on top of the current master, after > >committing the ScalarArrayOpExpr enhancements. I've updated the OR patch > >to get rid of the code duplication, and barring objections I'll get it > >committed shortly together with the two parts improving test coverage. > > > > I've pushed the two patches improving test coverage for functional > dependencies and MCV lists, which seems mostly non-controversial. I'll > wait a bit more with the two patches actually changing behavior (rebased > version attached, to keep cputube happy).
Some comment fixes: - /* Check if the expression the right shape (one Var, one Const) */ - if (!examine_clause_args(expr->args, &var, NULL, NULL)) + /* + * Check if the expression the right shape (one Var and one Const, + * or two Vars). + */ Check if the expression "has" or "is of" the right shape. - * Attempts to match the arguments to either (Var op Const) or (Const op Var), - * possibly with a RelabelType on top. When the expression matches this form, - * returns true, otherwise returns false. + * Attempts to match the arguments to either (Var op Const) or (Const op Var) + * or (Var op Var), possibly with a RelabelType on top. When the expression + * matches this form, returns true, otherwise returns false. ... match the arguments to (Var op Const), (Const op Var) or (Var op Var), ... + /* + * Both variables have to be for the same relation (otherwise it's + * a join clause, and we don't deal with those yet. + */ Missing close parenthesis. Stimulated by some bad plans involving JSON, I found my way to your WIP stats-on-expressions patch in this thread. Do I understand correctly that it will eventually also support single expressions, like CREATE STATISTICS t_distinct_abc (ndistinct) ON (my_jsonb_column->>'abc') FROM t? It looks like that would solve problems that otherwise require a generated column or an expression index just to get ndistinct.
