config: add an option to disable chunk (pingcap#5268)

config/config.go

@@ -34,6 +34,7 @@ type Config struct {
 	RunDDL       bool   `toml:"run-ddl" json:"run-ddl"`
 	SplitTable   bool   `toml:"split-table" json:"split-table"`
 	TokenLimit   int    `toml:"token-limit" json:"token-limit"`
+	EnableChunk  bool   `toml:"enable-chunk" json:"enable-chunk"`
 
 	Log               Log               `toml:"log" json:"log"`
 	Security          Security          `toml:"security" json:"security"`
@@ -147,13 +148,14 @@ type ProxyProtocol struct {
 }
 
 var defaultConf = Config{
-	Host:       "0.0.0.0",
-	Port:       4000,
-	Store:      "mocktikv",
-	Path:       "/tmp/tidb",
-	RunDDL:     true,
-	Lease:      "10s",
-	TokenLimit: 1000,
+	Host:        "0.0.0.0",
+	Port:        4000,
+	Store:       "mocktikv",
+	Path:        "/tmp/tidb",
+	RunDDL:      true,
+	Lease:       "10s",
+	TokenLimit:  1000,
+	EnableChunk: true,
 	Log: Log{
 		Level:  "info",
 		Format: "text",

config/config.toml.example

@@ -30,6 +30,9 @@ lease = "10s"
 # The limit of concurrent executed sessions.
 # token-limit = 1000
 
+# Enable chunk executors.
+enable-chunk = true
+
 [log]
 # Log level: info, debug, warn, error, fatal.
 level = "info"

server/conn.go

@@ -790,7 +790,7 @@ func (cc *clientConn) handleFieldList(sql string) (err error) {
 // resultsets, it's used to support the MULTI_RESULTS capability in mysql protocol.
 func (cc *clientConn) writeResultset(goCtx goctx.Context, rs ResultSet, binary bool, more bool) error {
 	defer terror.Call(rs.Close)
-	if rs.SupportChunk() {
+	if cc.server.cfg.EnableChunk && rs.SupportChunk() {
 		columns := rs.Columns()
 		err := cc.writeColumnInfo(columns)
 		if err != nil {