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 6567759595daad5c6317fbae22729d2e966f98cc..6eef1450e04eb89f6d31fa858da5de721123a7ef 100644 (file)
--- a/src/include/nodes/pathnodes.h
+++ b/src/include/nodes/pathnodes.h
@@ -1099,9 +1099,10 @@ 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,