From e9ef11ac8bb2acc2d2462fc17ec3291a959589e7 Mon Sep 17 00:00:00 2001 From: Alvaro Herrera Date: Thu, 12 Oct 2017 17:23:47 +0200 Subject: [PATCH] Infer functional dependency past RelabelType Vars hidden within a RelabelType would not be detected as compatible with some functional dependency. Repair by properly ignoring the RelabelType. Author: David Rowley Reviewed-by: Tomas Vondra Discussion: https://postgr.es/m/CAKJS1f-y-UEy=rsBXynBOgiW1fKMr_LVoYSGL9QOc36mLEC-ww@mail.gmail.com --- src/backend/statistics/dependencies.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/src/backend/statistics/dependencies.c b/src/backend/statistics/dependencies.c index 2e7c0ad6ba..9756fb83c0 100644 --- a/src/backend/statistics/dependencies.c +++ b/src/backend/statistics/dependencies.c @@ -792,6 +792,14 @@ dependency_is_compatible_clause(Node *clause, Index relid, AttrNumber *attnum) var = (varonleft) ? linitial(expr->args) : lsecond(expr->args); + /* + * We may ignore any RelabelType node above the operand. (There won't + * be more than one, since eval_const_expressions() has been applied + * already.) + */ + if (IsA(var, RelabelType)) + var = (Var *) ((RelabelType *) var)->arg; + /* We only support plain Vars for now */ if (!IsA(var, Var)) return false;