Remove GetDB from MigrationContext

Author: nikhilmat

go/base/context.go

@@ -200,9 +200,6 @@ type MigrationContext struct {
 	recentBinlogCoordinates mysql.BinlogCoordinates
 
 	CanStopStreaming func() bool
-
-	knownDBs      map[string]*gosql.DB
-	knownDBsMutex *sync.Mutex
 }
 
 type ContextConfig struct {
@@ -236,8 +233,6 @@ func NewMigrationContext() *MigrationContext {
 		pointOfInterestTimeMutex:            &sync.Mutex{},
 		ColumnRenameMap:                     make(map[string]string),
 		PanicAbort:                          make(chan error),
-		knownDBsMutex:                       &sync.Mutex{},
-		knownDBs:                            make(map[string]*gosql.DB),
 	}
 }
 
@@ -250,23 +245,6 @@ func getSafeTableName(baseName string, suffix string) string {
 	return fmt.Sprintf("_%s_%s", baseName[0:len(baseName)-extraCharacters], suffix)
 }
 
-// GetDB returns a DB instance based on uri.
-// bool result indicates whether the DB was returned from cache; err
-func (this *MigrationContext) GetDB(mysql_uri string) (*gosql.DB, bool, error) {
-	this.knownDBsMutex.Lock()
-	defer this.knownDBsMutex.Unlock()
-
-	var exists bool
-	if _, exists = this.knownDBs[mysql_uri]; !exists {
-		if db, err := sqlutils.GetDB(mysql_uri); err == nil {
-			this.knownDBs[mysql_uri] = db
-		} else {
-			return db, exists, err
-		}
-	}
-	return this.knownDBs[mysql_uri], exists, nil
-}
-
 // GetGhostTableName generates the name of ghost table, based on original table name
 // or a given table name
 func (this *MigrationContext) GetGhostTableName() string {