Revert "dump: retrieve ANSI_QUOTES from upstream (#909) (#929)"

dm/config/task.go

@@ -557,6 +557,8 @@ func (c *TaskConfig) SubTaskConfigs(sources map[string]DBConfig) ([]*SubTaskConf
 
 		cfg.CleanDumpFile = c.CleanDumpFile
 
+		cfg.EnableANSIQuotes = c.EnableANSIQuotes
+
 		err := cfg.Adjust(true)
 		if err != nil {
 			return nil, terror.Annotatef(err, "source %s", inst.SourceID)

mydumper/mydumper.go

@@ -17,8 +17,6 @@ import (
 	"bufio"
 	"bytes"
 	"context"
-	"database/sql"
-	"fmt"
 	"os"
 	"os/exec"
 	"regexp"
@@ -62,7 +60,6 @@ func NewMydumper(cfg *config.SubTaskConfig) *Mydumper {
 func (m *Mydumper) Init(ctx context.Context) error {
 	var err error
 	m.args, err = m.constructArgs()
-	m.detectAnsiQuotes()
 	return err
 }
 
@@ -319,24 +316,3 @@ func (m *Mydumper) logArgs(cfg *config.SubTaskConfig) []string {
 	}
 	return args
 }
-
-// detectAnsiQuotes tries to detect ANSI_QUOTES from upstream. If success, change EnableANSIQuotes in subtask config
-func (m *Mydumper) detectAnsiQuotes() {
-	dbCfg := m.cfg.From
-	dsn := fmt.Sprintf("%s:%s@tcp(%s:%d)/", dbCfg.User, dbCfg.Password, dbCfg.Host, dbCfg.Port)
-	db, err := sql.Open("mysql", dsn)
-	if err != nil {
-		return
-	}
-	defer db.Close()
-	enable, err := utils.HasAnsiQuotesMode(db)
-	if err != nil {
-		return
-	}
-	if enable != m.cfg.EnableANSIQuotes {
-		m.logger.Warn("found mismatched ANSI_QUOTES setting, going to overwrite it to DB specified",
-			zap.Bool("DB specified", enable),
-			zap.Bool("config file specified", m.cfg.EnableANSIQuotes))
-	}
-	m.cfg.EnableANSIQuotes = enable
-}