diff --git a/influxql/ast.go b/influxql/ast.go
index bb5161525aa..095b18a6bdb 100644
--- a/influxql/ast.go
+++ b/influxql/ast.go
@@ -1921,71 +1921,6 @@ func (s *SelectStatement) rewriteWithoutTimeDimensions() string {
 	return n.String()
 }
 
-/*
-
-BinaryExpr
-
-SELECT mean(xxx.value) + avg(yyy.value) FROM xxx JOIN yyy WHERE xxx.host = 123
-
-from xxx where host = 123
-select avg(value) from yyy where host = 123
-
-SELECT xxx.value FROM xxx WHERE xxx.host = 123
-SELECT yyy.value FROM yyy
-
----
-
-SELECT MEAN(xxx.value) + MEAN(cpu.load.value)
-FROM xxx JOIN yyy
-GROUP BY host
-WHERE (xxx.region == "uswest" OR yyy.region == "uswest") AND xxx.otherfield == "XXX"
-
-select * from (
-	select mean + mean from xxx join yyy
-	group by time(5m), host
-) (xxx.region == "uswest" OR yyy.region == "uswest") AND xxx.otherfield == "XXX"
-
-(seriesIDS for xxx.region = 'uswest' union seriesIDs for yyy.regnion = 'uswest') | seriesIDS xxx.otherfield = 'XXX'
-
-WHERE xxx.region == "uswest" AND xxx.otherfield == "XXX"
-WHERE yyy.region == "uswest"
-
-
-*/
-
-// Substatement returns a single-series statement for a given variable reference.
-func (s *SelectStatement) Substatement(ref *VarRef) (*SelectStatement, error) {
-	// Copy dimensions and properties to new statement.
-	other := &SelectStatement{
-		Fields:     Fields{{Expr: ref}},
-		Dimensions: s.Dimensions,
-		Limit:      s.Limit,
-		Offset:     s.Offset,
-		SortFields: s.SortFields,
-	}
-
-	// If there is only one series source then return it with the whole condition.
-	if len(s.Sources) == 1 {
-		other.Sources = s.Sources
-		other.Condition = s.Condition
-		return other, nil
-	}
-
-	// Find the matching source.
-	name := MatchSource(s.Sources, ref.Val)
-	if name == "" {
-		return nil, fmt.Errorf("field source not found: %s", ref.Val)
-	}
-	other.Sources = append(other.Sources, &Measurement{Name: name})
-
-	// Filter out conditions.
-	if s.Condition != nil {
-		other.Condition = filterExprBySource(name, s.Condition)
-	}
-
-	return other, nil
-}
-
 // NamesInWhere returns the field and tag names (idents) referenced in the where clause
 func (s *SelectStatement) NamesInWhere() []string {
 	var a []string
diff --git a/influxql/ast_test.go b/influxql/ast_test.go
index f7aeaf318f1..736fa42cf57 100644
--- a/influxql/ast_test.go
+++ b/influxql/ast_test.go
@@ -61,77 +61,6 @@ func TestDataType_String(t *testing.T) {
 	}
 }
 
-// Ensure the SELECT statement can extract substatements.
-func TestSelectStatement_Substatement(t *testing.T) {
-	var tests = []struct {
-		stmt string
-		expr *influxql.VarRef
-		sub  string
-		err  string
-	}{
-		// 0. Single series
-		{
-			stmt: `SELECT value FROM myseries WHERE value > 1`,
-			expr: &influxql.VarRef{Val: "value"},
-			sub:  `SELECT value FROM myseries WHERE value > 1`,
-		},
-
-		// 1. Simple join
-		{
-			stmt: `SELECT sum(aa.value) + sum(bb.value) FROM aa, bb`,
-			expr: &influxql.VarRef{Val: "aa.value"},
-			sub:  `SELECT "aa.value" FROM aa`,
-		},
-
-		// 2. Simple merge
-		{
-			stmt: `SELECT sum(aa.value) + sum(bb.value) FROM aa, bb`,
-			expr: &influxql.VarRef{Val: "bb.value"},
-			sub:  `SELECT "bb.value" FROM bb`,
-		},
-
-		// 3. Join with condition
-		{
-			stmt: `SELECT sum(aa.value) + sum(bb.value) FROM aa, bb WHERE aa.host = 'servera' AND bb.host = 'serverb'`,
-			expr: &influxql.VarRef{Val: "bb.value"},
-			sub:  `SELECT "bb.value" FROM bb WHERE "bb.host" = 'serverb'`,
-		},
-
-		// 4. Join with complex condition
-		{
-			stmt: `SELECT sum(aa.value) + sum(bb.value) FROM aa, bb WHERE aa.host = 'servera' AND (bb.host = 'serverb' OR bb.host = 'serverc') AND 1 = 2`,
-			expr: &influxql.VarRef{Val: "bb.value"},
-			sub:  `SELECT "bb.value" FROM bb WHERE ("bb.host" = 'serverb' OR "bb.host" = 'serverc') AND 1 = 2`,
-		},
-
-		// 5. 4 with different condition order
-		{
-			stmt: `SELECT sum(aa.value) + sum(bb.value) FROM aa, bb WHERE ((bb.host = 'serverb' OR bb.host = 'serverc') AND aa.host = 'servera') AND 1 = 2`,
-			expr: &influxql.VarRef{Val: "bb.value"},
-			sub:  `SELECT "bb.value" FROM bb WHERE (("bb.host" = 'serverb' OR "bb.host" = 'serverc')) AND 1 = 2`,
-		},
-	}
-
-	for i, tt := range tests {
-		// Parse statement.
-		stmt, err := influxql.NewParser(strings.NewReader(tt.stmt)).ParseStatement()
-		if err != nil {
-			t.Fatalf("invalid statement: %q: %s", tt.stmt, err)
-		}
-
-		// Extract substatement.
-		sub, err := stmt.(*influxql.SelectStatement).Substatement(tt.expr)
-		if err != nil {
-			t.Errorf("%d. %q: unexpected error: %s", i, tt.stmt, err)
-			continue
-		}
-		if substr := sub.String(); tt.sub != substr {
-			t.Errorf("%d. %q: unexpected substatement:\n\nexp=%s\n\ngot=%s\n\n", i, tt.stmt, tt.sub, substr)
-			continue
-		}
-	}
-}
-
 // Ensure the SELECT statement can extract GROUP BY interval.
 func TestSelectStatement_GroupByInterval(t *testing.T) {
 	q := "SELECT sum(value) from foo  where time < now() GROUP BY time(10m)"