Update PartitionTupleRouting struct comment

Small review on edd44738bc88.

Discussion: https://postgr.es/m/20180222165315.k27qfn4goskhoswj@alvherre.pgsql
Reviewed-by: Robert Haas, Amit Langote

diff --git a/src/include/executor/execPartition.h b/src/include/executor/execPartition.h
index e94718608fb987504aefecf71e73a9be1cdc3c12..03a599ad57a3cab619de6174827f17a885c793b6 100644 (file)
--- a/src/include/executor/execPartition.h
+++ b/src/include/executor/execPartition.h
@@ -58,11 +58,15 @@ typedef struct PartitionDispatchData *PartitionDispatch;
  *                             partition tree.
  * num_dispatch                    number of partitioned tables in the partition
  *                             tree (= length of partition_dispatch_info[])
- * partition_oids              Array of leaf partitions OIDs
+ * partition_oids              Array of leaf partitions OIDs with one entry
+ *                             for every leaf partition in the partition tree,
+ *                             initialized in full by
+ *                             ExecSetupPartitionTupleRouting.
  * partitions                  Array of ResultRelInfo* objects with one entry
- *                             for every leaf partition in the partition tree.
+ *                             for every leaf partition in the partition tree,
+ *                             initialized lazily by ExecInitPartitionInfo.
  * num_partitions              Number of leaf partitions in the partition tree
- *                             (= 'partitions' array length)
+ *                             (= 'partitions_oid'/'partitions' array length)
  * parent_child_tupconv_maps   Array of TupleConversionMap objects with one
  *                             entry for every leaf partition (required to
  *                             convert tuple from the root table's rowtype to