diff --git a/Modules.Base/Base/Base.vbproj b/Modules.Base/Base/Base.vbproj
index 891fb7be..3272f3ad 100644
--- a/Modules.Base/Base/Base.vbproj
+++ b/Modules.Base/Base/Base.vbproj
@@ -65,7 +65,8 @@
     <Import Include="System.Threading.Tasks" />
   </ItemGroup>
   <ItemGroup>
-    <Compile Include="NamedDatabase.vb" />
+    <Compile Include="Database\Enums.vb" />
+    <Compile Include="IDB\Database.vb" />
     <Compile Include="My Project\AssemblyInfo.vb" />
     <Compile Include="My Project\Application.Designer.vb">
       <AutoGen>True</AutoGen>
diff --git a/Modules.Base/Base/Database/Enums.vb b/Modules.Base/Base/Database/Enums.vb
new file mode 100644
index 00000000..3e0cbe6b
--- /dev/null
+++ b/Modules.Base/Base/Database/Enums.vb
@@ -0,0 +1,8 @@
+Namespace Database
+    Module Enums
+        Public Enum NamedDatabase
+            ECM
+            IDB
+        End Enum
+    End Module
+End Namespace
diff --git a/Modules.Base/Base/IDB/Database.vb b/Modules.Base/Base/IDB/Database.vb
new file mode 100644
index 00000000..f86b7186
--- /dev/null
+++ b/Modules.Base/Base/IDB/Database.vb
@@ -0,0 +1,15 @@
+
+Namespace IDB
+    ''' <summary>
+    ''' This module is intended for often used constants and datastructures
+    ''' Therefor it is important that this module does not have any dependencies on other modules!!
+    ''' </summary>
+    Module Constants
+        Public Const OBJECT_STATE_FILE_ADDED = "File added"
+        Public Const OBJECT_STATE_FILE_VERSIONED = "File versioned"
+        Public Const OBJECT_STATE_FILE_CHANGED = "File changed"
+        Public Const OBJECT_STATE_FILE_DELETED = "File deleted"
+        Public Const OBJECT_STATE_METADATA_CHANGED = "Metadata changed"
+        Public Const OBJECT_STATE_ATTRIBUTEVALUE_DELETED = "Attributevalue deleted"
+    End Module
+End Namespace
diff --git a/Modules.Base/Base/NamedDatabase.vb b/Modules.Base/Base/NamedDatabase.vb
deleted file mode 100644
index 011c88c7..00000000
--- a/Modules.Base/Base/NamedDatabase.vb
+++ /dev/null
@@ -1,10 +0,0 @@
-''' <summary>
-''' This module is intended for often used constants and datastructures
-''' Therefor it is important that this module does not have any dependencies on other modules!!
-''' </summary>
-Namespace Constants
-    Public Enum NamedDatabase
-        ECM
-        IDB
-    End Enum
-End Namespace
diff --git a/Modules.Database/Adapters/MSSQLServer.vb b/Modules.Database/Adapters/MSSQLServer.vb
index 4beb217c..e8bd14d5 100644
--- a/Modules.Database/Adapters/MSSQLServer.vb
+++ b/Modules.Database/Adapters/MSSQLServer.vb
@@ -278,7 +278,7 @@ Public Class MSSQLServer
         End Try
     End Function
 
-    <DebuggerStepThrough()>
+    '<DebuggerStepThrough()>
     Public Function GetDatatable(SqlCommand As String) As DataTable Implements IDatabase.GetDatatable
         Return GetDatatable(SqlCommand, _Timeout)
     End Function
@@ -294,19 +294,19 @@ Public Class MSSQLServer
         End Using
     End Function
 
-    <DebuggerStepThrough()>
+    '<DebuggerStepThrough()>
     Public Function GetDatatable(SqlCommand As String, Transaction As SqlTransaction, Optional Timeout As Integer = 120) As DataTable
         Using oSqlConnection = GetSQLConnection()
             Return GetDatatableWithConnectionObject(SqlCommand, oSqlConnection, TransactionMode.ExternalTransaction, Transaction, Timeout)
         End Using
     End Function
 
-    <DebuggerStepThrough()>
+    '<DebuggerStepThrough()>
     Public Async Function GetDatatableAsync(SqlCommand As String, Optional Timeout As Integer = 120) As Task(Of DataTable)
         Return Await Task.Run(Function() GetDatatable(SqlCommand, Timeout))
     End Function
 
-    <DebuggerStepThrough()>
+    '<DebuggerStepThrough()>
     Public Function GetDatatableWithConnection(SqlCommand As String, ConnectionString As String, Optional Timeout As Integer = 120) As DataTable
         Using oConnection = GetConnection(ConnectionString)
             Return GetDatatableWithConnectionObject(SqlCommand, oConnection, Timeout:=Timeout)
@@ -342,33 +342,33 @@ Public Class MSSQLServer
         Return oTable
     End Function
 
-    <DebuggerStepThrough()>
+    '<DebuggerStepThrough()>
     Public Function ExecuteNonQuery(SQLCommand As String) As Boolean Implements IDatabase.ExecuteNonQuery
         Using oConnection = GetSQLConnection()
             Return ExecuteNonQueryWithConnectionObject(SQLCommand, oConnection, TransactionMode.WithTransaction, Nothing, _Timeout)
         End Using
     End Function
 
-    <DebuggerStepThrough()>
+    '<DebuggerStepThrough()>
     Public Function ExecuteNonQuery(SQLCommand As String, Timeout As Integer) As Boolean Implements IDatabase.ExecuteNonQuery
         Using oConnection = GetSQLConnection()
             Return ExecuteNonQueryWithConnectionObject(SQLCommand, oConnection, TransactionMode.WithTransaction, Nothing, Timeout)
         End Using
     End Function
 
-    <DebuggerStepThrough()>
+    '<DebuggerStepThrough()>
     Public Function ExecuteNonQuery(SQLCommand As String, Transaction As SqlTransaction, Optional Timeout As Integer = 120) As Boolean
         Using oConnection = GetSQLConnection()
             Return ExecuteNonQueryWithConnectionObject(SQLCommand, Transaction.Connection, TransactionMode.ExternalTransaction, Transaction, Timeout)
         End Using
     End Function
 
-    <DebuggerStepThrough()>
+    '<DebuggerStepThrough()>
     Public Async Function ExecuteNonQueryAsync(SQLCommand As String, Optional Timeout As Integer = 120) As Task(Of Boolean)
         Return Await Task.Run(Function() ExecuteNonQuery(SQLCommand, Timeout))
     End Function
 
-    <DebuggerStepThrough()>
+    '<DebuggerStepThrough()>
     Public Function ExecuteNonQueryWithConnection(pSQLCommand As String, ConnString As String, Optional Timeout As Integer = 120) As Boolean
         Using oConnection = GetConnection(ConnString)
             Return ExecuteNonQueryWithConnectionObject(pSQLCommand, oConnection, TransactionMode.WithTransaction, Nothing, Timeout)
@@ -399,33 +399,33 @@ Public Class MSSQLServer
         End Try
     End Function
 
-    <DebuggerStepThrough()>
+    '<DebuggerStepThrough()>
     Public Function GetScalarValue(SQLQuery As String) As Object Implements IDatabase.GetScalarValue
         Using oConnection As SqlConnection = GetSQLConnection()
             Return GetScalarValueWithConnectionObject(SQLQuery, oConnection)
         End Using
     End Function
 
-    <DebuggerStepThrough()>
+    '<DebuggerStepThrough()>
     Public Function GetScalarValue(SQLCommand As String, Timeout As Integer) As Object Implements IDatabase.GetScalarValue
         Using oConnection = GetSQLConnection()
             Return GetScalarValueWithConnectionObject(SQLCommand, oConnection, TransactionMode.WithTransaction, Nothing, Timeout)
         End Using
     End Function
 
-    <DebuggerStepThrough()>
+    '<DebuggerStepThrough()>
     Public Function GetScalarValue(SQLCommand As String, Transaction As SqlTransaction, Optional Timeout As Integer = 120) As Object
         Using oConnection = GetSQLConnection()
             Return GetScalarValueWithConnectionObject(SQLCommand, oConnection, TransactionMode.ExternalTransaction, Transaction, Timeout)
         End Using
     End Function
 
-    <DebuggerStepThrough()>
+    '<DebuggerStepThrough()>
     Public Async Function GetScalarValueAsync(SQLQuery As String, Optional Timeout As Integer = 120) As Task(Of Object)
         Return Await Task.Run(Function() GetScalarValue(SQLQuery, Timeout))
     End Function
 
-    <DebuggerStepThrough()>
+    '<DebuggerStepThrough()>
     Public Function GetScalarValueWithConnection(SQLCommand As String, ConnectionString As String, Optional Timeout As Integer = 120) As Object
         Using oConnection = GetConnection(ConnectionString)
             Return GetScalarValueWithConnectionObject(SQLCommand, oConnection, TransactionMode.WithTransaction, Nothing, Timeout)
@@ -490,7 +490,7 @@ Public Class MSSQLServer
         End Try
     End Function
 
-    <DebuggerStepThrough()>
+    '<DebuggerStepThrough()>
     Public Function GetScalarValue(SQLCommand As SqlCommand, OutputParameter As String) As Object
         Return GetScalarValue(SQLCommand, OutputParameter, _Timeout)
     End Function
@@ -521,7 +521,7 @@ Public Class MSSQLServer
         End Try
     End Sub
 
-    <DebuggerStepThrough()>
+    '<DebuggerStepThrough()>
     Private Sub NewExecuteNonQueryAsync_Callback(ByVal result As IAsyncResult)
         Dim command As SqlCommand = CType(result.AsyncState, SqlCommand)
         Dim res = command.EndExecuteNonQuery(result)
diff --git a/Modules.Filesystem/File.vb b/Modules.Filesystem/File.vb
index 7425e2d3..1c109f8f 100644
--- a/Modules.Filesystem/File.vb
+++ b/Modules.Filesystem/File.vb
@@ -75,6 +75,11 @@ Public Class File
         Return oCleanName
     End Function
 
+    ''' <summary>
+    ''' Reads the file at `FilePath` and computes a SHA256 Hash from its contents
+    ''' </summary>
+    ''' <param name="FilePath"></param>
+    ''' <returns></returns>
     Public Function GetChecksum(FilePath As String) As String
         Try
             Using oFileStream = IO.File.OpenRead(FilePath)
@@ -339,6 +344,24 @@ Public Class File
         End Try
     End Function
 
+    ''' <summary>
+    ''' Checks if a file is locked, ie. in use by another process.
+    ''' </summary>
+    ''' <remarks>
+    ''' https://docs.microsoft.com/en-us/dotnet/standard/io/handling-io-errors
+    ''' </remarks>
+    Public Function TestFileIsLocked(pFilePath As String) As Boolean
+        Try
+            Using stream As FileStream = IO.File.Open(FileMode.Open, FileAccess.Read, FileShare.None)
+                stream.Close()
+            End Using
+        Catch ex As Exception When ((ex.HResult And &HFFFF) = 32)
+            Return True
+        End Try
+
+        Return False
+    End Function
+
     Public Function TestPathIsDirectory(Path As String) As Boolean
         If Not Directory.Exists(Path) Then
             Return False