opt,sqltelemetry: added a counter for OrderByNullsStandardCounter

Prior to this commit, we only had a counter for uses of non-standard
NULLs ordering. This commit adds a counter for standard NULLs ordering
so we can compare the two.

Release note: None

pkg/sql/opt/optbuilder/orderby.go

@@ -287,6 +287,7 @@ func (b *Builder) hasDefaultNullsOrder(order *tree.Order) bool {
 		telemetry.Inc(sqltelemetry.OrderByNullsNonStandardCounter)
 		return false
 	}
+	telemetry.Inc(sqltelemetry.OrderByNullsStandardCounter)
 	return true
 }
 

pkg/sql/sqltelemetry/planning.go

@@ -132,6 +132,11 @@ var CreateStatisticsUseCounter = telemetry.GetCounterOnce("sql.plan.stats.create
 // FIRST).
 var OrderByNullsNonStandardCounter = telemetry.GetCounterOnce("sql.plan.opt.order-by-nulls-non-standard")
 
+// OrderByNullsStandardCounter is to be incremented whenever a standard
+// ordering of nulls is used for ORDER BY (either ASC NULLS FIRST or DESC NULLS
+// LAST).
+var OrderByNullsStandardCounter = telemetry.GetCounterOnce("sql.plan.opt.order-by-nulls-standard")
+
 // TurnAutoStatsOnUseCounter is to be incremented whenever automatic stats
 // collection is explicitly enabled.
 var TurnAutoStatsOnUseCounter = telemetry.GetCounterOnce("sql.plan.automatic-stats.enabled")