Fix example plan in optimizer/README.

tglsfdc · tglsfdc · commit 3c821466abcd · 2017-01-23T09:38:36.000-05:00
Joining three tables only takes two join nodes. I think when I (tgl) wrote this, I was envisioning possible additional joins; but since the example doesn't show any fourth table, it's just confusing to write a third join node. Etsuro Fujita Discussion: https://postgr.es/m/e6cfbaa3-af02-1abc-c25e-8fa5c6bc4e21@lab.ntt.co.jp
diff --git a/src/backend/optimizer/README b/src/backend/optimizer/README
@@ -757,9 +757,8 @@ to create a plan like
         -> Seq Scan on SmallTable1 A
         NestLoop
             -> Seq Scan on SmallTable2 B
-            NestLoop
-                -> Index Scan using XYIndex on LargeTable C
-                      Index Condition: C.X = A.AID and C.Y = B.BID
+            -> Index Scan using XYIndex on LargeTable C
+                 Index Condition: C.X = A.AID and C.Y = B.BID
 
 so we should be willing to pass down A.AID through a join even though
 there is no join order constraint forcing the plan to look like this.
