Fix incorrect IndexOptInfo header comment

The comment incorrectly indicated that indexcollations[] stored
collations for both key columns and INCLUDE columns, but in reality it
only has elements for the key columns.  canreturn[] didn't get a mention,
so add that while we're here.

Author: Junwang Zhao <zhjwpku@gmail.com>
Reviewed-by: David Rowley <dgrowleyml@gmail.com>
Discussion: https://postgr.es/m/CAEG8a3LwbZgMKOQ9CmZarX5DEipKivdHp5PZMOO-riL0w%3DL%3D4A%40mail.gmail.com
Backpatch-through: 14

diff --git a/src/include/nodes/pathnodes.h b/src/include/nodes/pathnodes.h
index 9d804d4b32189831f5a1a313d2d12418fc1fbfd2..d9b24861199e9a7703af22e3bd42b67dde91e228 100644 (file)
--- a/src/include/nodes/pathnodes.h
+++ b/src/include/nodes/pathnodes.h
@@ -800,9 +800,10 @@ typedef struct RelOptInfo
  * IndexOptInfo
  *     Per-index information for planning/optimization
  *
- *     indexkeys[], indexcollations[] each have ncolumns entries.
- *     opfamily[], and opcintype[] each have nkeycolumns entries. They do
- *     not contain any information about included attributes.
+ *     indexkeys[] and canreturn[] each have ncolumns entries.
+ *
+ *     indexcollations[], opfamily[], and opcintype[] each have nkeycolumns
+ *     entries.  These don't contain any information about INCLUDE columns.
  *
  *     sortopfamily[], reverse_sort[], and nulls_first[] have
  *     nkeycolumns entries, if the index is ordered; but if it is unordered,