Installation

• MS SQL Server Management Studio (SSMS)
• 4 server SQL with name: NGANHANG, NGANHANG1, NGANHANG2, NGANHANG3 with same database name NGANHANG. All setup for replication them in scripts/ folder
• Service: Sql Server Agent (avoid use sql server edtion express which missing this feature) and Microsoft Distribute Transaction Coordinator are runnings.
• Change sql login user sa and remote login password in Program.cs for appropriate with publisher database
• Visual studio .NET and DevExpress for winforms compatible with version of visual studio

Visual studio 2017 and DevExpress 19.2.5 are used for create this project

Archtechture

Features

• Distribute transaction
• Parallel query with sql agent job
• Implement undo, redo feature via command pattern

---

Advantage

• Database system able to scaling horizontally
• Speed up query when find data from smaller database. Especially when query for local database instead of remote database server
• Parallel query able to gather data from many database, speed up query execution by optimize many computer hardware

Downside

• Slow data synchronize of mssql server replication technology make different result from many aspect in a distribute transaction for a while.
• Hard to manager connection to many database via network
• In this project there is no strategy to handle single point of failure