diff --git a/src/backend/executor/execPartition.c b/src/backend/executor/execPartition.c
index 954a96c696..224d4fc879 100644
--- a/src/backend/executor/execPartition.c
+++ b/src/backend/executor/execPartition.c
@@ -970,20 +970,15 @@ get_partition_dispatch_recurse(Relation rel, Relation parent,
 	 * partitions are processed as well and a corresponding PartitionDispatch
 	 * object gets added to *pds.
 	 *
-	 * About the values in pd->indexes: for a leaf partition, it contains the
-	 * leaf partition's position in the global list *leaf_part_oids minus 1,
-	 * whereas for a partitioned table partition, it contains the partition's
-	 * position in the global list *pds multiplied by -1.  The latter is
-	 * multiplied by -1 to distinguish partitioned tables from leaf partitions
-	 * when going through the values in pd->indexes.  So, for example, when
-	 * using it during tuple-routing, encountering a value >= 0 means we found
-	 * a leaf partition.  It is immediately returned as the index in the array
-	 * of ResultRelInfos of all the leaf partitions, using which we insert the
-	 * tuple into that leaf partition.  A negative value means we found a
-	 * partitioned table.  The value multiplied by -1 is returned as the index
-	 * in the array of PartitionDispatch objects of all partitioned tables in
-	 * the tree.  This value is used to continue the search in the next level
-	 * of the partition tree.
+	 * The 'indexes' array is used when searching for a partition matching a
+	 * given tuple.  The actual value we store here depends on if the array
+	 * element belongs to a leaf partition or a subpartitioned table.  For
+	 * leaf partitions we store the 0-based index into *leaf_part_oids, and
+	 * for sub-partitioned tables we store a negative version of the index
+	 * into the *pds list.  When searching, we know when we see a negative
+	 * value that the search must continue in the corresponding sub-partition,
+	 * or if we find a positive value then we've identified the correct
+	 * partition.
 	 */
 	pd->indexes = (int *) palloc(partdesc->nparts * sizeof(int));
 	for (i = 0; i < partdesc->nparts; i++)