RE: Hybrid Hash/Nested Loop joins and caching results from subplans

> I've attached the updated patch.  I'll let the CFbot grab this to ensure it's
> happy with it before I go looking to push it again.

Hi,

I took a look into the patch and noticed some minor things.

1.
+        case T_ResultCache:
+            ptype = "ResultCache";
+            subpath = ((ResultCachePath *) path)->subpath;
+            break;
         case T_UniquePath:
             ptype = "Unique";
             subpath = ((UniquePath *) path)->subpath;
should we use "case T_ResultCachePath" here?

2.
Is it better to add ResultCache's info to " src/backend/optimizer/README " ?
Something like:
  NestPath      - nested-loop joins
  MergePath     - merge joins
  HashPath      - hash joins
+ ResultCachePath - Result cache

Best regards,
Hou zhijie