From 002aca3f68d0b72132c8e994d0fb16b6442bf87b Mon Sep 17 00:00:00 2001
From: Salvo 'LtWorf' Tomaselli <tiposchi@tiscali.it>
Date: Sat, 9 Apr 2016 10:07:44 +0200
Subject: [PATCH] Only holds for union

Does not hold for other operations.
---
 relational/optimizations.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/relational/optimizations.py b/relational/optimizations.py
index d36c409..c637fbf 100644
--- a/relational/optimizations.py
+++ b/relational/optimizations.py
@@ -546,14 +546,14 @@ def projection_and_union(n, rels):
     if A and B are union compatible
     '''
     changes = 0
-    if n.name in {UNION, INTERSECTION, DIFFERENCE} and \
+    if n.name == UNION and \
             n.left.name == PROJECTION and \
             n.right.name == PROJECTION and \
             set(n.left.child.result_format(rels)) == set(n.right.child.result_format(rels)):
         newchild = parser.Node()
 
         newchild.kind = parser.BINARY
-        newchild.name = n.name
+        newchild.name = UNION
         newchild.left = n.left.child
         newchild.right = n.right.child