Address reviews

src/backend/timeseries/create_timeseries_table.c

@@ -198,6 +198,12 @@ InitiateTimeseriesTablePartitions(Oid relationId, bool useStartFrom)
 {
 	bool readOnly = false;
 	StringInfo initiateTimeseriesPartitionsCommand = makeStringInfo();
+
+	/*
+	 * Since making the right calculation via C is much more complex and
+	 * we will call that function once to create timeseries table, we
+	 * are using SPI call.
+	 */
 	if (useStartFrom)
 	{
 		appendStringInfo(initiateTimeseriesPartitionsCommand,

src/include/timeseries/timeseries_utils.h

@@ -25,6 +25,10 @@
 #define Anum_citus_timeseries_table_compression_threshold 6
 #define Anum_citus_timeseries_table_retention_threshold 7
 
+/*
+ * Taken from the Postgres code. Postgres' uses that conversion
+ * for internal interval conparison.
+ */
 #define INTERVAL_TO_SEC(ivp) \
 	(((double) (ivp)->time) / ((double) USECS_PER_SEC) + \
 	 (ivp)->day * (24.0 * SECS_PER_HOUR) + \