diff --git a/store/driver/txn/txn_driver.go b/store/driver/txn/txn_driver.go
index 72c1aac8c8e71..7c940561f82fe 100644
--- a/store/driver/txn/txn_driver.go
+++ b/store/driver/txn/txn_driver.go
@@ -168,8 +168,6 @@ func (txn *tikvTxn) SetOption(opt int, val interface{}) {
 		txn.KVTxn.GetSnapshot().SetIsStatenessReadOnly(val.(bool))
 	case kv.MatchStoreLabels:
 		txn.KVTxn.GetSnapshot().SetMatchStoreLabels(val.([]*metapb.StoreLabel))
-	default:
-		txn.KVTxn.SetOption(opt, val)
 	}
 }
 
@@ -180,7 +178,7 @@ func (txn *tikvTxn) GetOption(opt int) interface{} {
 	case kv.TxnScope:
 		return txn.KVTxn.GetScope()
 	default:
-		return txn.KVTxn.GetOption(opt)
+		return nil
 	}
 }
 
@@ -188,8 +186,6 @@ func (txn *tikvTxn) DelOption(opt int) {
 	switch opt {
 	case kv.CollectRuntimeStats:
 		txn.KVTxn.GetSnapshot().SetRuntimeStats(nil)
-	default:
-		txn.KVTxn.DelOption(opt)
 	}
 }
 
diff --git a/store/tikv/txn.go b/store/tikv/txn.go
index e444f5adda7f6..aafaa2b323d24 100644
--- a/store/tikv/txn.go
+++ b/store/tikv/txn.go
@@ -221,22 +221,6 @@ func (txn *KVTxn) Delete(k []byte) error {
 	return txn.us.GetMemBuffer().Delete(k)
 }
 
-// SetOption sets an option with a value, when val is nil, uses the default
-// value of this option.
-func (txn *KVTxn) SetOption(opt int, val interface{}) {
-	txn.us.SetOption(opt, val)
-}
-
-// GetOption returns the option
-func (txn *KVTxn) GetOption(opt int) interface{} {
-	return txn.us.GetOption(opt)
-}
-
-// DelOption deletes an option.
-func (txn *KVTxn) DelOption(opt int) {
-	txn.us.DelOption(opt)
-}
-
 // SetSchemaLeaseChecker sets a hook to check schema version.
 func (txn *KVTxn) SetSchemaLeaseChecker(checker SchemaLeaseChecker) {
 	txn.schemaLeaseChecker = checker
diff --git a/store/tikv/unionstore/union_store.go b/store/tikv/unionstore/union_store.go
index f9a077d1c1352..08354975e38c5 100644
--- a/store/tikv/unionstore/union_store.go
+++ b/store/tikv/unionstore/union_store.go
@@ -59,7 +59,6 @@ type uSnapshot interface {
 type KVUnionStore struct {
 	memBuffer *MemDB
 	snapshot  uSnapshot
-	opts      options
 }
 
 // NewUnionStore builds a new unionStore.
@@ -67,7 +66,6 @@ func NewUnionStore(snapshot uSnapshot) *KVUnionStore {
 	return &KVUnionStore{
 		snapshot:  snapshot,
 		memBuffer: newMemDB(),
-		opts:      make(map[int]interface{}),
 	}
 }
 
@@ -131,30 +129,8 @@ func (us *KVUnionStore) UnmarkPresumeKeyNotExists(k []byte) {
 	us.memBuffer.UpdateFlags(k, kv.DelPresumeKeyNotExists)
 }
 
-// SetOption implements the unionStore SetOption interface.
-func (us *KVUnionStore) SetOption(opt int, val interface{}) {
-	us.opts[opt] = val
-}
-
-// DelOption implements the unionStore DelOption interface.
-func (us *KVUnionStore) DelOption(opt int) {
-	delete(us.opts, opt)
-}
-
-// GetOption implements the unionStore GetOption interface.
-func (us *KVUnionStore) GetOption(opt int) interface{} {
-	return us.opts[opt]
-}
-
 // SetEntrySizeLimit sets the size limit for each entry and total buffer.
 func (us *KVUnionStore) SetEntrySizeLimit(entryLimit, bufferLimit uint64) {
 	us.memBuffer.entrySizeLimit = entryLimit
 	us.memBuffer.bufferSizeLimit = bufferLimit
 }
-
-type options map[int]interface{}
-
-func (opts options) Get(opt int) (interface{}, bool) {
-	v, ok := opts[opt]
-	return v, ok
-}