satellite/satellitedb: simplify select nodes query construction

Change-Id: I07009b28762d4485929a2a999e8f4be8179bee51

satellite/overlay/benchmark_test.go

@@ -206,6 +206,10 @@ func BenchmarkNodeSelection(b *testing.B) {
 			OnlineWindow:     time.Hour,
 			DistinctIP:       true,
 			MinimumDiskSpace: 0,
+			AsOfSystemTime: overlay.AsOfSystemTimeConfig{
+				Enabled:         true,
+				DefaultInterval: -time.Microsecond,
+			},
 		}
 
 		var excludedIDs []storj.NodeID
@@ -285,6 +289,7 @@ func BenchmarkNodeSelection(b *testing.B) {
 			MinimumVersion:     "v1.0.0",
 			OnlineWindow:       time.Hour,
 			DistinctIP:         false,
+			AsOfSystemInterval: -time.Microsecond,
 		}
 		excludedCriteria := &overlay.NodeCriteria{
 			FreeDisk:           0,
@@ -293,6 +298,7 @@ func BenchmarkNodeSelection(b *testing.B) {
 			MinimumVersion:     "v1.0.0",
 			OnlineWindow:       time.Hour,
 			DistinctIP:         false,
+			AsOfSystemInterval: -time.Microsecond,
 		}
 
 		b.Run("SelectStorageNodes", func(b *testing.B) {
@@ -365,6 +371,7 @@ func BenchmarkNodeSelection(b *testing.B) {
 					RequestedCount:     SelectCount,
 					ExcludedIDs:        nil,
 					MinimumVersion:     "v1.0.0",
+					AsOfSystemInterval: -time.Microsecond,
 				}, &nodeSelectionConfig)
 				require.NoError(b, err)
 				require.NotEmpty(b, selected)
@@ -377,6 +384,7 @@ func BenchmarkNodeSelection(b *testing.B) {
 					RequestedCount:     SelectCount,
 					ExcludedIDs:        excludedIDs,
 					MinimumVersion:     "v1.0.0",
+					AsOfSystemInterval: -time.Microsecond,
 				}, &nodeSelectionConfig)
 				require.NoError(b, err)
 				require.NotEmpty(b, selected)
@@ -389,6 +397,7 @@ func BenchmarkNodeSelection(b *testing.B) {
 					RequestedCount:     SelectCount,
 					ExcludedIDs:        nil,
 					MinimumVersion:     "v1.0.0",
+					AsOfSystemInterval: -time.Microsecond,
 				})
 				require.NoError(b, err)
 				require.NotEmpty(b, selected)
@@ -401,6 +410,7 @@ func BenchmarkNodeSelection(b *testing.B) {
 					RequestedCount:     SelectCount,
 					ExcludedIDs:        excludedIDs,
 					MinimumVersion:     "v1.0.0",
+					AsOfSystemInterval: -time.Microsecond,
 				})
 				require.NoError(b, err)
 				require.NotEmpty(b, selected)
@@ -413,6 +423,7 @@ func BenchmarkNodeSelection(b *testing.B) {
 					RequestedCount:     SelectCount,
 					ExcludedIDs:        nil,
 					MinimumVersion:     "v1.0.0",
+					AsOfSystemInterval: -time.Microsecond,
 				})
 				require.NoError(b, err)
 				require.NotEmpty(b, selected)
@@ -425,6 +436,7 @@ func BenchmarkNodeSelection(b *testing.B) {
 					RequestedCount:     SelectCount,
 					ExcludedIDs:        excludedIDs,
 					MinimumVersion:     "v1.0.0",
+					AsOfSystemInterval: -time.Microsecond,
 				})
 				require.NoError(b, err)
 				require.NotEmpty(b, selected)

satellite/satellitedb/nodeselection.go

@@ -104,43 +104,38 @@ func (cache *overlaycache) selectStorageNodesOnce(ctx context.Context, reputable
 
 	var reputableNodeQuery, newNodeQuery partialQuery
 
-	asOf := cache.db.impl.AsOfSystemInterval(criteria.AsOfSystemInterval)
-
 	// Note: the true/false at the end of each selection string indicates if the selection is for new nodes or not.
 	// Later, the flag allows us to distinguish if a node is new when scanning the db rows.
 	if !criteria.DistinctIP {
 		reputableNodeQuery = partialQuery{
-			selection:  `SELECT last_net, id, address, last_ip_port, false FROM nodes ` + asOf,
+			selection: `SELECT last_net, id, address, last_ip_port, false FROM nodes`,
 			condition: reputableNodesCondition,
 			limit:     reputableNodeCount,
-			aostClause: asOf,
 		}
 		newNodeQuery = partialQuery{
-			selection:  `SELECT last_net, id, address, last_ip_port, true FROM nodes ` + asOf,
+			selection: `SELECT last_net, id, address, last_ip_port, true FROM nodes`,
 			condition: newNodesCondition,
 			limit:     newNodeCount,
-			aostClause: asOf,
 		}
 	} else {
 		reputableNodeQuery = partialQuery{
-			selection:  `SELECT DISTINCT ON (last_net) last_net, id, address, last_ip_port, false FROM nodes ` + asOf,
+			selection: `SELECT DISTINCT ON (last_net) last_net, id, address, last_ip_port, false FROM nodes`,
 			condition: reputableNodesCondition,
 			distinct:  true,
 			limit:     reputableNodeCount,
 			orderBy:   "last_net",
-			aostClause: asOf,
 		}
 		newNodeQuery = partialQuery{
-			selection:  `SELECT DISTINCT ON (last_net) last_net, id, address, last_ip_port, true FROM nodes ` + asOf,
+			selection: `SELECT DISTINCT ON (last_net) last_net, id, address, last_ip_port, true FROM nodes`,
 			condition: newNodesCondition,
 			distinct:  true,
 			limit:     newNodeCount,
 			orderBy:   "last_net",
-			aostClause: asOf,
 		}
 	}
 
-	query := unionAll(asOf, newNodeQuery, reputableNodeQuery)
+	query := unionAll(newNodeQuery, reputableNodeQuery)
+	query.query = cache.db.impl.WrapAsOfSystemInterval(query.query, criteria.AsOfSystemInterval)
 
 	rows, err := cache.db.Query(ctx, cache.db.Rebind(query.query), query.args...)
 	if err != nil {
@@ -243,7 +238,6 @@ type partialQuery struct {
 	distinct  bool
 	orderBy   string
 	limit     int
-	aostClause string
 }
 
 // isEmpty returns whether the result for the query is definitely empty.
@@ -274,7 +268,7 @@ func (partial partialQuery) asQuery() query {
 		fmt.Fprint(&q, " LIMIT ? ")
 		args = append(args, partial.limit)
 	} else {
-		fmt.Fprint(&q, ") filtered "+partial.aostClause+" ORDER BY RANDOM() LIMIT ?")
+		fmt.Fprint(&q, ") filtered ORDER BY RANDOM() LIMIT ?")
 		args = append(args, partial.limit)
 	}
 
@@ -282,7 +276,7 @@ func (partial partialQuery) asQuery() query {
 }
 
 // unionAll combines multiple partial queries into a single query.
-func unionAll(asOf string, partials ...partialQuery) query {
+func unionAll(partials ...partialQuery) query {
 	var queries []string
 	var args []interface{}
 	for _, partial := range partials {
@@ -302,16 +296,8 @@ func unionAll(asOf string, partials ...partialQuery) query {
 		return query{query: queries[0], args: args}
 	}
 
-	union := "(" + strings.Join(queries, ") UNION ALL (") + ")"
-	if asOf == "" {
 	return query{
-			query: union,
+		query: "(" + strings.Join(queries, ") UNION ALL (") + ")",
-			args:  args,
-		}
-	}
-
-	return query{
-		query: "SELECT * FROM (" + union + ") " + asOf,
 		args:  args,
 	}
 }