On Sun, Apr 7, 2024 at 6:28 PM Alexander Korotkov <akorot...@postgresql.org> wrote: > > Transform OR clauses to ANY expression > > Replace (expr op C1) OR (expr op C2) ... with expr op ANY(ARRAY[C1, C2, ...]) > on the preliminary stage of optimization when we are still working with the > expression tree. > > Here Cn is a n-th constant expression, 'expr' is non-constant expression, 'op' > is an operator which returns boolean result and has a commuter (for the case > of reverse order of constant and non-constant parts of the expression, > like 'Cn op expr'). > > Sometimes it can lead to not optimal plan. This is why there is a > or_to_any_transform_limit GUC. It specifies a threshold value of length of > arguments in an OR expression that triggers the OR-to-ANY transformation. > Generally, more groupable OR arguments mean that transformation will be more > likely to win than to lose.
I'm getting this warning now /src/backend/optimizer/prep/prepqual.c:582:33: warning: declaration of ‘lc__state’ shadows a previous local [-Wshadow=compatible-local] 582 | foreach(lc, entry->consts)
