add query settings interface

connection.go

@@ -22,6 +22,7 @@ const (
 type odpsConn struct {
 	*http.Client
 	*Config
+	hints map[string]string
 }
 
 // ODPS does not support transaction
@@ -129,7 +130,7 @@ func (conn *odpsConn) wait(query string, args []driver.Value) (string, error) {
 		query = fmt.Sprintf(query, args)
 	}
 
-	ins, err := conn.createInstance(newSQLJob(query))
+	ins, err := conn.createInstance(newSQLJob(query, conn.hints))
 	if err != nil {
 		return "", err
 	}

driver.go

@@ -8,16 +8,26 @@ import (
 
 // register driver
 func init() {
-	sql.Register("maxcompute", &Driver{})
+	sql.Register("maxcompute", &MaxcomputeDriver{})
 }
 
-// impls database/sql/driver.Driver
-type Driver struct{}
+// MaxcomputeDriver impls database/sql/driver.Driver
+type MaxcomputeDriver struct {
+	conn odpsConn
+}
 
-func (d Driver) Open(dsn string) (driver.Conn, error) {
+func (o MaxcomputeDriver) Open(dsn string) (driver.Conn, error) {
 	cfg, err := ParseDSN(dsn)
 	if err != nil {
 		return nil, err
 	}
-	return &odpsConn{&http.Client{}, cfg}, nil
+	o.conn = odpsConn{&http.Client{}, cfg, nil}
+	return &o.conn, nil
+}
+
+// SetQuerySettings sets the global query settings.
+// TODO(Yancey1989): add the one-off query settings interface.
+func (o MaxcomputeDriver) SetQuerySettings(hints map[string]string) error {
+	o.conn.hints = hints
+	return nil
 }

driver_test.go

@@ -21,3 +21,12 @@ func TestSQLOpen(t *testing.T) {
 	defer db.Close()
 	a.NoError(err)
 }
+
+func TestQuerySettings(t *testing.T) {
+	a := assert.New(t)
+	db, err := sql.Open("maxcompute", cfg4test.FormatDSN())
+	a.NoError(err)
+	db.Driver().(*MaxcomputeDriver).SetQuerySettings(map[string]string{"odps.sql.mapper.split.size": "16"})
+	_, err = db.Query("SELECT * FROM gomaxcompute_test LIMIT;")
+	a.NoError(err)
+}

job.go

@@ -25,8 +25,8 @@ func newJob(tasks ...odpsTask) *odpsJob {
 	}
 }
 
-func newSQLJob(sql string) *odpsJob {
-	return newJob(newAnonymousSQLTask(sql, nil))
+func newSQLJob(sql string, hints map[string]string) *odpsJob {
+	return newJob(newAnonymousSQLTask(sql, hints))
 }
 
 func (j *odpsJob) MarshalXML(e *xml.Encoder, start xml.StartElement) (err error) {

task.go

@@ -73,6 +73,10 @@ func newSQLTask(name, query string, config map[string]string) odpsTask {
 			"uuid":     uuid.NewV4().String(),
 			"settings": `{"odps.sql.udf.strict.mode": "true"}`,
 		}
+	} else {
+		if _, ok := config["uuid"]; !ok {
+			config["uuid"] = uuid.NewV4().String()
+		}
 	}
 	// maxcompute sql ends with a ';'
 	query = strings.TrimSpace(query)