diff --git a/database/database.go b/database/database.go
index 8874bdc542416e1807793fad8799646de31a39b9..5f33a14dcb6c095a69dd0f23e4cb32272dafb947 100644
--- a/database/database.go
+++ b/database/database.go
@@ -81,6 +81,7 @@ func storePndTxFunc(name, description string, interfaces []string) neo4j.Transac
 		})
 
 		if err != nil {
+			//TODO: handle neo4j.isServiceUnavailable()
 			return nil, err
 		}
 
@@ -115,6 +116,9 @@ func (d Database) GetNodesByLabel(label string) {}
 
 func (d Database) GetDeviceByID(id string) {}
 
+//storeNodesTxFunc transaction to store devices from a json.
+//relates them to a specific pnd id.
+//returns a slice of added devices
 func storeNodesTxFunc(json string, id int64) neo4j.TransactionWork {
 	return func(tx neo4j.Transaction) (interface{}, error) {
 		var nodelist []neo4j.Node
@@ -142,6 +146,7 @@ func storeNodesTxFunc(json string, id int64) neo4j.TransactionWork {
 		})
 
 		if err != nil {
+			//TODO: handle neo4j.isServiceUnavailable()
 			return nil, err
 		}
 
@@ -182,6 +187,9 @@ func (d Database) RemoveNodes(json string) {}
 //RemoveSingleNode removes the given node and their relationship by id.
 func (d Database) RemoveSingleNode(id string) {}
 
+//storeLinksTxFunc transaction to store links from a json.
+//creates relation between different devices.
+//returns a slice of those created relations.
 func storeLinksTxFunc(json string) neo4j.TransactionWork {
 	return func(tx neo4j.Transaction) (interface{}, error) {
 		var relationsList []neo4j.Relationship
@@ -203,6 +211,7 @@ func storeLinksTxFunc(json string) neo4j.TransactionWork {
 		})
 
 		if err != nil {
+			//TODO: handle neo4j.isServiceUnavailable()
 			return nil, err
 		}
 
@@ -233,6 +242,8 @@ func (d Database) StoreLinks(json string) []neo4j.Relationship {
 	return result.([]neo4j.Relationship)
 }
 
+//storeNodeEdgePointsTxFunc transaction to store interfaces from a json.
+//returns count of added/updated interfaces
 func storeNodeEdgePointsTxFunc(json string) neo4j.TransactionWork {
 	return func(tx neo4j.Transaction) (interface{}, error) {
 		query :=
@@ -253,6 +264,7 @@ func storeNodeEdgePointsTxFunc(json string) neo4j.TransactionWork {
 		})
 
 		if err != nil {
+			//TODO: handle neo4j.isServiceUnavailable()
 			return nil, err
 		}
 
@@ -264,9 +276,11 @@ func storeNodeEdgePointsTxFunc(json string) neo4j.TransactionWork {
 	}
 }
 
-//TODO: currently this goes over each and every device and interface and adds
+//TODO: currently this goes over each and every device/interface and adds
 //		a interface_of relation. -> do it only for the newly added interfaces
-//		returns count of created relations
+
+//storeNodeEdgePointsRelationTxFunc transaction to create relations between interfaces and devices
+//returns count of added/updated relations
 func storeNodeEdgePointsRelationTxFunc() neo4j.TransactionWork {
 	return func(tx neo4j.Transaction) (interface{}, error) {
 		query :=
@@ -280,6 +294,7 @@ func storeNodeEdgePointsRelationTxFunc() neo4j.TransactionWork {
 		result, err := tx.Run(query, nil)
 
 		if err != nil {
+			//TODO: handle neo4j.isServiceUnavailable()
 			return nil, err
 		}