perf: cache reserved bind variables in queries

go/test/fuzzing/parser_fuzzer.go

@@ -28,13 +28,13 @@ func FuzzIsDML(data []byte) int {
 }
 
 func FuzzNormalizer(data []byte) int {
-	stmt, err := sqlparser.Parse(string(data))
+	stmt, reservedVars, err := sqlparser.Parse2(string(data))
 	if err != nil {
 		return -1
 	}
 	prefix := "bv"
 	bv := make(map[string]*querypb.BindVariable)
-	sqlparser.Normalize(stmt, bv, prefix)
+	sqlparser.Normalize(stmt, reservedVars, bv, prefix)
 	return 1
 }
 

go/vt/sqlparser/ast_rewriting.go

@@ -33,9 +33,9 @@ type RewriteASTResult struct {
 }
 
 // PrepareAST will normalize the query
-func PrepareAST(in Statement, bindVars map[string]*querypb.BindVariable, prefix string, parameterize bool, keyspace string) (*RewriteASTResult, error) {
+func PrepareAST(in Statement, reservedVars BindVars, bindVars map[string]*querypb.BindVariable, prefix string, parameterize bool, keyspace string) (*RewriteASTResult, error) {
 	if parameterize {
-		err := Normalize(in, bindVars, prefix)
+		err := Normalize(in, reservedVars, bindVars, prefix)
 		if err != nil {
 			return nil, err
 		}

go/vt/sqlparser/normalizer.go

@@ -24,15 +24,18 @@ import (
 	querypb "vitess.io/vitess/go/vt/proto/query"
 )
 
+// BindVars is a set of reserved bind variables from a SQL statement
+type BindVars map[string]struct{}
+
 // Normalize changes the statement to use bind values, and
 // updates the bind vars to those values. The supplied prefix
 // is used to generate the bind var names. The function ensures
 // that there are no collisions with existing bind vars.
 // Within Select constructs, bind vars are deduped. This allows
 // us to identify vindex equality. Otherwise, every value is
 // treated as distinct.
-func Normalize(stmt Statement, bindVars map[string]*querypb.BindVariable, prefix string) error {
-	nz := newNormalizer(stmt, bindVars, prefix)
+func Normalize(stmt Statement, known BindVars, bindVars map[string]*querypb.BindVariable, prefix string) error {
+	nz := newNormalizer(known, bindVars, prefix)
 	_, err := Rewrite(stmt, nz.WalkStatement, nil)
 	if err != nil {
 		return err
@@ -49,11 +52,11 @@ type normalizer struct {
 	err      error
 }
 
-func newNormalizer(stmt Statement, bindVars map[string]*querypb.BindVariable, prefix string) *normalizer {
+func newNormalizer(reserved map[string]struct{}, bindVars map[string]*querypb.BindVariable, prefix string) *normalizer {
 	return &normalizer{
 		bindVars: bindVars,
 		prefix:   prefix,
-		reserved: GetBindvars(stmt),
+		reserved: reserved,
 		counter:  1,
 		vals:     make(map[string]string),
 	}
@@ -226,8 +229,6 @@ func (nz *normalizer) newName() string {
 }
 
 // GetBindvars returns a map of the bind vars referenced in the statement.
-// TODO(sougou); This function gets called again from vtgate/planbuilder.
-// Ideally, this should be done only once.
 func GetBindvars(stmt Statement) map[string]struct{} {
 	bindvars := make(map[string]struct{})
 	_ = Walk(func(node SQLNode) (kontinue bool, err error) {

go/vt/sqlparser/normalizer_test.go

@@ -230,9 +230,10 @@ func TestNormalize(t *testing.T) {
 			t.Error(err)
 			continue
 		}
+		known := GetBindvars(stmt)
 		bv := make(map[string]*querypb.BindVariable)
 		require.NoError(t,
-			Normalize(stmt, bv, prefix))
+			Normalize(stmt, known, bv, prefix))
 		outstmt := String(stmt)
 		if outstmt != tc.outstmt {
 			t.Errorf("Query:\n%s:\n%s, want\n%s", tc.in, outstmt, tc.outstmt)
@@ -269,12 +270,43 @@ BenchmarkNormalize-8      500000              3620 ns/op            1461 B/op
 */
 func BenchmarkNormalize(b *testing.B) {
 	sql := "select 'abcd', 20, 30.0, eid from a where 1=eid and name='3'"
-	ast, err := Parse(sql)
+	ast, reservedVars, err := Parse2(sql)
 	if err != nil {
 		b.Fatal(err)
 	}
 	for i := 0; i < b.N; i++ {
 		require.NoError(b,
-			Normalize(ast, map[string]*querypb.BindVariable{}, ""))
+			Normalize(ast, reservedVars, map[string]*querypb.BindVariable{}, ""))
+	}
+}
+
+func BenchmarkNormalizeTraces(b *testing.B) {
+	for _, trace := range []string{"django_queries.txt", "lobsters.sql.gz"} {
+		b.Run(trace, func(b *testing.B) {
+			queries := loadQueries(b, trace)
+			if len(queries) > 10000 {
+				queries = queries[:10000]
+			}
+
+			parsed := make([]Statement, 0, len(queries))
+			reservedVars := make([]BindVars, 0, len(queries))
+			for _, q := range queries {
+				pp, kb, err := Parse2(q)
+				if err != nil {
+					b.Fatal(err)
+				}
+				parsed = append(parsed, pp)
+				reservedVars = append(reservedVars, kb)
+			}
+
+			b.ResetTimer()
+			b.ReportAllocs()
+
+			for i := 0; i < b.N; i++ {
+				for i, query := range parsed {
+					_ = Normalize(query, reservedVars[i], map[string]*querypb.BindVariable{}, "")
+				}
+			}
+		})
 	}
 }

go/vt/sqlparser/parser.go

@@ -68,27 +68,34 @@ func yyParsePooled(yylex yyLexer) int {
 // a set of types, define the function as iTypeName.
 // This will help avoid name collisions.
 
-// Parse parses the SQL in full and returns a Statement, which
-// is the AST representation of the query. If a DDL statement
+// Parse2 parses the SQL in full and returns a Statement, which
+// is the AST representation of the query, and a set of BindVars, which are all the
+// bind variables that were found in the original SQL query. If a DDL statement
 // is partially parsed but still contains a syntax error, the
 // error is ignored and the DDL is returned anyway.
-func Parse(sql string) (Statement, error) {
+func Parse2(sql string) (Statement, BindVars, error) {
 	tokenizer := NewStringTokenizer(sql)
 	if yyParsePooled(tokenizer) != 0 {
 		if tokenizer.partialDDL != nil {
 			if typ, val := tokenizer.Scan(); typ != 0 {
-				return nil, fmt.Errorf("extra characters encountered after end of DDL: '%s'", string(val))
+				return nil, nil, fmt.Errorf("extra characters encountered after end of DDL: '%s'", string(val))
 			}
 			log.Warningf("ignoring error parsing DDL '%s': %v", sql, tokenizer.LastError)
 			tokenizer.ParseTree = tokenizer.partialDDL
-			return tokenizer.ParseTree, nil
+			return tokenizer.ParseTree, tokenizer.BindVars, nil
 		}
-		return nil, vterrors.New(vtrpcpb.Code_INVALID_ARGUMENT, tokenizer.LastError.Error())
+		return nil, nil, vterrors.New(vtrpcpb.Code_INVALID_ARGUMENT, tokenizer.LastError.Error())
 	}
 	if tokenizer.ParseTree == nil {
-		return nil, ErrEmpty
+		return nil, nil, ErrEmpty
 	}
-	return tokenizer.ParseTree, nil
+	return tokenizer.ParseTree, tokenizer.BindVars, nil
+}
+
+// Parse behaves like Parse2 but does not return a set of bind variables
+func Parse(sql string) (Statement, error) {
+	stmt, _, err := Parse2(sql)
+	return stmt, err
 }
 
 // ParseStrictDDL is the same as Parse except it errors on

go/vt/sqlparser/redact_query.go

@@ -23,13 +23,13 @@ func RedactSQLQuery(sql string) (string, error) {
 	bv := map[string]*querypb.BindVariable{}
 	sqlStripped, comments := SplitMarginComments(sql)
 
-	stmt, err := Parse(sqlStripped)
+	stmt, reservedVars, err := Parse2(sqlStripped)
 	if err != nil {
 		return "", err
 	}
 
 	prefix := "redacted"
-	err = Normalize(stmt, bv, prefix)
+	err = Normalize(stmt, reservedVars, bv, prefix)
 	if err != nil {
 		return "", err
 	}