diff --git a/Core/DB/IDBConnection.cs b/Core/DB/IDBConnection.cs
index 9e844a8..b67d80d 100644
--- a/Core/DB/IDBConnection.cs
+++ b/Core/DB/IDBConnection.cs
@@ -11,13 +11,15 @@ namespace FLocal.Core.DB {
 
 		int[] LoadIdsByConditions(ITableSpec table, conditions.AbstractCondition conditions, Diapasone diapasone, JoinSpec[] joins, SortSpec[] sorts);
 
-		ILock lockTable(ITableSpec table);
+		Transaction beginTransaction();
 
-		ILock lockRow(ITableSpec table, int id);
+		ILock lockTable(Transaction transaction, ITableSpec table);
 
-		void update(ITableSpec table, int id, Dictionary<string, string> data);
+		ILock lockRow(Transaction transaction, ITableSpec table, int id);
 
-		void delete(ITableSpec table, int id); //do we really need this?
+		void update(Transaction transaction, ITableSpec table, int id, Dictionary<string, string> data);
+
+		void delete(Transaction transaction, ITableSpec table, int id); //do we really need this?
 
 	}
 
diff --git a/Core/DB/ITransaction.cs b/Core/DB/ITransaction.cs
new file mode 100644
index 0000000..5a18ff9
--- /dev/null
+++ b/Core/DB/ITransaction.cs
@@ -0,0 +1,41 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace FLocal.Core.DB {
+
+	abstract class Transaction : IDisposable {
+
+		abstract protected void do_Commit();
+
+		abstract protected void do_Rollback();
+
+		private bool finalized = false;
+
+		public void Commit() {
+			lock(this) {
+				this.do_Commit();
+				this.finalized = true;
+			}
+		}
+
+		public void Rollback() {
+			lock(this) {
+				this.do_Rollback();
+				this.finalized = true;
+			}
+		}
+
+		public void Dispose() {
+			lock(this) {
+				if(!this.finalized) {
+					this.do_Rollback();
+					this.finalized = true;
+				}
+			}
+		}
+
+	}
+
+}