diff --git a/db/model/merge.go b/db/model/merge.go
index 97257b4..ef490d8 100644
--- a/db/model/merge.go
+++ b/db/model/merge.go
@@ -76,7 +76,7 @@
 		}
 	}
 	for v, _ := range changes.KeyMap1 {
-		if _, ok := changes.KeyMap2[v]; ok && lst1[changes.KeyMap1[v]].GetHash() != lst1[changes.KeyMap2[v]].GetHash() {
+		if _, ok := changes.KeyMap2[v]; ok && lst1[changes.KeyMap1[v]].GetHash() != lst2[changes.KeyMap2[v]].GetHash() {
 			changes.ChangedKeys[v] = struct{}{}
 		}
 	}
@@ -100,7 +100,7 @@
 		configChanged = true
 	}
 
-	newChildren := reflect.ValueOf(dstRev.GetChildren()).Elem().Interface().(map[string][]Revision)
+	newChildren := reflect.ValueOf(dstRev.GetChildren()).Interface().(map[string][]Revision)
 	childrenFields := ChildrenFields(forkRev.GetData())
 
 	for fieldName, field := range childrenFields {
@@ -108,7 +108,7 @@
 		srcList := srcRev.GetChildren()[fieldName]
 		dstList := dstRev.GetChildren()[fieldName]
 
-		if revisionsAreEqual(forkList, srcList) {
+		if revisionsAreEqual(dstList, srcList) {
 			for _, rev := range srcList {
 				mergeChildFunc(rev)
 			}
@@ -126,7 +126,7 @@
 					if field.IsContainer {
 						changes = append(
 							changes, ChangeTuple{POST_LISTCHANGE,
-							NewOperationContext("", nil, fieldName, "")},
+								NewOperationContext("", nil, fieldName, "")},
 						)
 					}
 				}
@@ -139,23 +139,30 @@
 			if revisionsAreEqual(dstList, forkList) {
 				src := newChangeAnalysis(forkList, srcList, field.Key)
 
-				newList := reflect.ValueOf(srcList).Elem().Interface().([]Revision)
+				newList := reflect.ValueOf(srcList).Interface().([]Revision)
 
 				for key, _ := range src.AddedKeys {
-					idx := src.KeyMap1[key]
+					idx := src.KeyMap2[key]
 					newRev := mergeChildFunc(newList[idx])
-					newList[idx] = newRev
 
-					changes = append(changes, ChangeTuple{POST_ADD,newRev.GetData()})
+					// FIXME: newRev may come back as nil... exclude those entries for now
+					if newRev != nil {
+						newList[idx] = newRev
+						changes = append(changes, ChangeTuple{POST_ADD, newRev.GetData()})
+					}
 				}
 				for key, _ := range src.RemovedKeys {
 					oldRev := forkList[src.KeyMap1[key]]
-					changes = append(changes, ChangeTuple{POST_REMOVE,oldRev.GetData()})
+					changes = append(changes, ChangeTuple{POST_REMOVE, oldRev.GetData()})
 				}
 				for key, _ := range src.ChangedKeys {
 					idx := src.KeyMap2[key]
 					newRev := mergeChildFunc(newList[idx])
-					newList[idx] = newRev
+
+					// FIXME: newRev may come back as nil... exclude those entries for now
+					if newRev != nil {
+						newList[idx] = newRev
+					}
 				}
 
 				newChildren[fieldName] = newList
@@ -163,7 +170,7 @@
 				src := newChangeAnalysis(forkList, srcList, field.Key)
 				dst := newChangeAnalysis(forkList, dstList, field.Key)
 
-				newList := reflect.ValueOf(dstList).Elem().Interface().([]Revision)
+				newList := reflect.ValueOf(dstList).Interface().([]Revision)
 
 				for key, _ := range src.AddedKeys {
 					if _, exists := dst.AddedKeys[key]; exists {
@@ -177,7 +184,7 @@
 					} else {
 						newRev := mergeChildFunc(srcList[src.KeyMap2[key]])
 						newList = append(newList, newRev)
-						changes = append(changes, ChangeTuple{POST_ADD,newRev.GetData()})
+						changes = append(changes, ChangeTuple{POST_ADD, newRev.GetData()})
 					}
 				}
 				for key, _ := range src.ChangedKeys {
@@ -213,7 +220,7 @@
 						newList[len(newList)-1] = nil
 						newList = newList[:len(newList)-1]
 
-						changes = append(changes, ChangeTuple{POST_REMOVE,oldRev.GetData()})
+						changes = append(changes, ChangeTuple{POST_REMOVE, oldRev.GetData()})
 					}
 				}
 
@@ -233,10 +240,11 @@
 		rev = rev.UpdateAllChildren(newChildren, dstRev.GetBranch())
 
 		if configChanged {
-			changes = append(changes, ChangeTuple{POST_UPDATE,rev.GetData()})
+			changes = append(changes, ChangeTuple{POST_UPDATE, rev.GetData()})
 		}
 		return rev, changes
-	}
+	} else {
+		return nil, nil
 
-	return nil, nil
+	}
 }
diff --git a/db/model/node.go b/db/model/node.go
index 77e0cc7..0a77fff 100644
--- a/db/model/node.go
+++ b/db/model/node.go
@@ -15,6 +15,9 @@
  */
 package model
 
+// TODO: proper error handling
+// TODO: proper logging
+
 import (
 	"fmt"
 	"github.com/golang/protobuf/proto"
@@ -590,7 +593,7 @@
 		childBranch := rev.GetBranch()
 
 		if childBranch.Txid == txid {
-			rev = childBranch.Node.mergeTxBranch(txid, dryRun)
+			rev, _ = childBranch.Node.mergeTxBranch(txid, dryRun)
 		}
 
 		return rev
@@ -598,7 +601,7 @@
 	return f
 }
 
-func (n *Node) mergeTxBranch(txid string, dryRun bool) Revision {
+func (n *Node) mergeTxBranch(txid string, dryRun bool) (Revision, error) {
 	srcBranch := n.Branches[txid]
 	dstBranch := n.Branches[NONE]
 
@@ -613,7 +616,8 @@
 		delete(n.Branches, txid)
 	}
 
-	return rev
+	// TODO: return proper error when one occurs
+	return rev, nil
 }
 
 // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Diff utility ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
diff --git a/db/model/non_persisted_revision.go b/db/model/non_persisted_revision.go
index 26d25a0..4a97941 100644
--- a/db/model/non_persisted_revision.go
+++ b/db/model/non_persisted_revision.go
@@ -188,7 +188,7 @@
 }
 
 func (npr *NonPersistedRevision) UpdateAllChildren(children map[string][]Revision, branch *Branch) Revision {
-	newRev := reflect.ValueOf(npr).Interface().(NonPersistedRevision)
+	newRev := reflect.ValueOf(npr).Elem().Interface().(NonPersistedRevision)
 	newRev.SetBranch(branch)
 	newRev.SetChildren(children)
 	newRev.Finalize()
diff --git a/db/model/proxy.go b/db/model/proxy.go
index 79087a3..4b7a59f 100644
--- a/db/model/proxy.go
+++ b/db/model/proxy.go
@@ -82,7 +82,7 @@
 	} else {
 		fullPath = p.Path + path
 	}
-	return p.Node.Update(fullPath, data, strict, txid, nil)
+	return p.Root.Update(fullPath, data, strict, txid, nil)
 }
 
 func (p *Proxy) Add(path string, data interface{}, txid string) interface{} {
@@ -96,7 +96,7 @@
 	} else {
 		fullPath = p.Path + path
 	}
-	return p.Node.Add(fullPath, data, txid, nil)
+	return p.Root.Add(fullPath, data, txid, nil)
 }
 
 func (p *Proxy) Remove(path string, txid string) interface{} {
@@ -110,7 +110,7 @@
 	} else {
 		fullPath = p.Path + path
 	}
-	return p.Node.Remove(fullPath, txid, nil)
+	return p.Root.Remove(fullPath, txid, nil)
 }
 
 func (p *Proxy) openTransaction() *Transaction {
diff --git a/db/model/root.go b/db/model/root.go
index d10e9f1..b4885c1 100644
--- a/db/model/root.go
+++ b/db/model/root.go
@@ -27,7 +27,7 @@
 
 type Root struct {
 	*Node
-	DirtyNodes            map[string]*Node
+	DirtyNodes            map[string][]*Node
 	KvStore               *Backend
 	Loading               bool
 	RevisionClass         interface{}
@@ -38,7 +38,7 @@
 func NewRoot(initialData interface{}, kvStore *Backend, revisionClass interface{}) *Root {
 	root := &Root{}
 	root.KvStore = kvStore
-	root.DirtyNodes = make(map[string]*Node)
+	root.DirtyNodes = make(map[string][]*Node)
 	root.Loading = false
 	if kvStore != nil /*&& TODO: RevisionClass is not a subclass of PersistedRevision ??? */ {
 		revisionClass = reflect.TypeOf(PersistedRevision{})
@@ -63,23 +63,23 @@
 func (r *Root) MakeTxBranch() string {
 	txid_bin, _ := uuid.New().MarshalBinary()
 	txid := hex.EncodeToString(txid_bin)[:12]
-	r.DirtyNodes[txid] = r.Node
+	r.DirtyNodes[txid] = []*Node{r.Node}
 	r.Node.makeTxBranch(txid)
 	return txid
 }
 
 func (r *Root) DeleteTxBranch(txid string) {
-	for _, dirtyNode := range r.DirtyNodes {
+	for _, dirtyNode := range r.DirtyNodes[txid] {
 		dirtyNode.deleteTxBranch(txid)
 	}
 	delete(r.DirtyNodes, txid)
 }
 
 func (r *Root) FoldTxBranch(txid string) {
-	if err := r.Node.mergeTxBranch(txid, true); err != nil {
+	if _, err := r.mergeTxBranch(txid, true); err != nil {
 		r.DeleteTxBranch(txid)
 	} else {
-		r.Node.mergeTxBranch(txid, false)
+		r.mergeTxBranch(txid, false)
 		r.executeCallbacks()
 	}
 }
@@ -120,10 +120,8 @@
 	}
 
 	if txid != "" {
-		//dirtied := r.DirtyNodes[txid]
-
 		trackDirty := func(node *Node) *Branch {
-			//dirtied.Add(Node)
+			r.DirtyNodes[txid] = append(r.DirtyNodes[txid], node)
 			return node.makeTxBranch(txid)
 		}
 		result = r.Node.Update(path, data, strict, txid, trackDirty)
@@ -148,10 +146,8 @@
 	}
 
 	if txid != "" {
-		//dirtied := r.DirtyNodes[txid]
-
 		trackDirty := func(node *Node) *Branch {
-			//dirtied.Add(Node)
+			r.DirtyNodes[txid] = append(r.DirtyNodes[txid], node)
 			return node.makeTxBranch(txid)
 		}
 		result = r.Node.Add(path, data, txid, trackDirty)
@@ -176,10 +172,8 @@
 	}
 
 	if txid != "" {
-		//dirtied := r.DirtyNodes[txid]
-
 		trackDirty := func(node *Node) *Branch {
-			//dirtied.Add(Node)
+			r.DirtyNodes[txid] = append(r.DirtyNodes[txid], node)
 			return node.makeTxBranch(txid)
 		}
 		result = r.Node.Remove(path, txid, trackDirty)
diff --git a/db/model/transaction.go b/db/model/transaction.go
index 1bed0d1..0ee3643 100644
--- a/db/model/transaction.go
+++ b/db/model/transaction.go
@@ -29,34 +29,34 @@
 	}
 	return tx
 }
-func (t *Transaction) Get(path string, depth int, deep bool) Revision {
+func (t *Transaction) Get(path string, depth int, deep bool) interface{} {
 	if t.txid == "" {
 		fmt.Errorf("closed transaction")
 		return nil
 	}
 	// TODO: need to review the return values at the different layers!!!!!
-	return t.proxy.Get(path, depth, deep, t.txid).(Revision)
+	return t.proxy.Get(path, depth, deep, t.txid)
 }
-func (t *Transaction) Update(path string, data interface{}, strict bool) Revision {
+func (t *Transaction) Update(path string, data interface{}, strict bool) interface{} {
 	if t.txid == "" {
 		fmt.Errorf("closed transaction")
 		return nil
 	}
-	return t.proxy.Update(path, data, strict, t.txid).(Revision)
+	return t.proxy.Update(path, data, strict, t.txid)
 }
-func (t *Transaction) Add(path string, data interface{}) Revision {
+func (t *Transaction) Add(path string, data interface{}) interface{} {
 	if t.txid == "" {
 		fmt.Errorf("closed transaction")
 		return nil
 	}
-	return t.proxy.Add(path, data, t.txid).(Revision)
+	return t.proxy.Add(path, data, t.txid)
 }
-func (t *Transaction) Remove(path string) Revision {
+func (t *Transaction) Remove(path string) interface{} {
 	if t.txid == "" {
 		fmt.Errorf("closed transaction")
 		return nil
 	}
-	return t.proxy.Remove(path, t.txid).(Revision)
+	return t.proxy.Remove(path, t.txid)
 }
 func (t *Transaction) Cancel() {
 	t.proxy.cancelTransaction(t.txid)
diff --git a/db/model/transaction_test.go b/db/model/transaction_test.go
new file mode 100644
index 0000000..4a0cc29
--- /dev/null
+++ b/db/model/transaction_test.go
@@ -0,0 +1,157 @@
+/*
+ * Copyright 2018-present Open Networking Foundation
+
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+
+ * http://www.apache.org/licenses/LICENSE-2.0
+
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package model
+
+import (
+	"github.com/opencord/voltha-go/protos/voltha"
+	"github.com/opencord/voltha-go/common/log"
+	"testing"
+	"github.com/google/uuid"
+	"encoding/hex"
+	"strconv"
+	"reflect"
+)
+
+type transactionTest struct {
+	Root        *Root
+	Backend     *Backend
+	Proxy       *Proxy
+	DbPrefix    string
+	DbType      string
+	DbHost      string
+	DbPort      int
+	DbTimeout   int
+}
+
+var (
+	tx = &transactionTest{
+		DbPrefix: "service/voltha/data/core/0001",
+		DbType:   "etcd",
+		//DbHost:    "10.102.58.0",
+		DbHost:    "localhost",
+		DbPort:    2379,
+		DbTimeout: 5,
+	}
+	txTargetDevId string
+	txDevId string
+)
+
+func init() {
+	if _, err := log.SetLogger(log.CONSOLE, 0, log.Fields{"instanceId": "transaction_test"}); err != nil {
+		log.With(log.Fields{"error": err}).Fatal("cannot setup logging")
+	}
+	defer log.CleanUp()
+
+	tx.Backend = NewBackend(tx.DbType, tx.DbHost, tx.DbPort, tx.DbTimeout, tx.DbPrefix)
+
+	msgClass := &voltha.Voltha{}
+	root := NewRoot(msgClass, tx.Backend, nil)
+	tx.Root = root.Load(msgClass)
+
+	GetProfiling().Report()
+
+	tx.Proxy = tx.Root.Node.GetProxy("/", false)
+
+}
+
+func Test_Transaction_1_GetDevices(t *testing.T) {
+	getTx := tx.Proxy.openTransaction()
+
+	devices := getTx.Get("/devices", 1, false)
+
+	if len(devices.([]interface{})) == 0 {
+		t.Error("there are no available devices to retrieve")
+	} else {
+		// Save the target device id for later tests
+		txTargetDevId = devices.([]interface{})[0].(*voltha.Device).Id
+		t.Logf("retrieved devices: %+v", devices)
+	}
+
+	tx.Proxy.commitTransaction(getTx.txid)
+}
+
+func Test_Transaction_2_GetDevice(t *testing.T) {
+
+	basePath := "/devices/" + txTargetDevId
+
+	getDevWithPortsTx := tx.Proxy.openTransaction()
+	device1 := getDevWithPortsTx.Get(basePath+"/ports", 1, false)
+	t.Logf("retrieved device with ports: %+v", device1)
+	tx.Proxy.commitTransaction(getDevWithPortsTx.txid)
+
+	getDevTx := tx.Proxy.openTransaction()
+	device2 := getDevTx.Get(basePath, 0, false)
+	t.Logf("retrieved device: %+v", device2)
+	tx.Proxy.commitTransaction(getDevTx.txid)
+}
+
+func Test_Transaction_3_AddDevice(t *testing.T) {
+	devIdBin, _ := uuid.New().MarshalBinary()
+	txDevId = "0001" + hex.EncodeToString(devIdBin)[:12]
+
+	device := &voltha.Device{
+		Id:         txDevId,
+		Type:       "simulated_olt",
+		Address:    &voltha.Device_HostAndPort{HostAndPort: "1.2.3.4:5555"},
+		AdminState: voltha.AdminState_PREPROVISIONED,
+	}
+
+	addTx := tx.Proxy.openTransaction()
+
+	if added := addTx.Add("/devices", device); added == nil {
+		t.Error("Failed to add device")
+	} else {
+		t.Logf("Added device : %+v", added)
+	}
+	tx.Proxy.commitTransaction(addTx.txid)
+}
+
+func Test_Transaction_4_UpdateDevice(t *testing.T) {
+	updateTx := tx.Proxy.openTransaction()
+	if retrieved := updateTx.Get("/devices/"+txTargetDevId, 1, false); retrieved == nil {
+		t.Error("Failed to get device")
+	} else {
+		var fwVersion int
+		if retrieved.(*voltha.Device).FirmwareVersion == "n/a" {
+			fwVersion = 0
+		} else {
+			fwVersion, _ = strconv.Atoi(retrieved.(*voltha.Device).FirmwareVersion)
+			fwVersion += 1
+		}
+
+		cloned := reflect.ValueOf(retrieved).Elem().Interface().(voltha.Device)
+		cloned.FirmwareVersion = strconv.Itoa(fwVersion)
+		t.Logf("Before update : %+v", cloned)
+
+		// FIXME: The makeBranch passed in function is nil or not being executed properly!!!!!
+		if afterUpdate := updateTx.Update("/devices/"+txTargetDevId, &cloned, false); afterUpdate == nil {
+			t.Error("Failed to update device")
+		} else {
+			t.Logf("Updated device : %+v", afterUpdate.(Revision).GetData())
+		}
+	}
+	tx.Proxy.commitTransaction(updateTx.txid)
+}
+
+func Test_Transaction_5_RemoveDevice(t *testing.T) {
+	removeTx := tx.Proxy.openTransaction()
+	if removed := removeTx.Remove("/devices/"+txDevId); removed == nil {
+		t.Error("Failed to remove device")
+	} else {
+		t.Logf("Removed device : %+v", removed)
+	}
+	tx.Proxy.commitTransaction(removeTx.txid)
+}