Understanding Transaction Replication in SQL Server 2025 –A Complete Guide

When working with databases, one of the most common requirements is to share data between multiple servers in real-time. In SQL Server 2025, Transaction Replication remains one of the most reliable methods to achieve this.

In this blog, I’ll explain what Transaction Replication is, how it works, its key components, and why you should use it.

What Is Transaction Replication in SQL Server 2025?

Transaction Replication is a method of copying data changes (transactions) from one database (the Publisher) to another (the Subscriber) almost in real-time.

• Every time an insert, update, or delete happens in the Publisher database, those changes are immediately delivered to the Subscriber database.

• This makes it perfect for reporting environments, distributed applications, or when multiple systems need the same data at the same time.

New in SQL Server 2025 – Cross-Platform Replication

In earlier versions, replication was mainly restricted to Windows-to-Windows environments. With SQL Server 2025, Microsoft has extended support for:

• Windows → Linux replication

• Linux → Windows replication

• Linux → Linux replication

This means if your company runs mixed environments (for example, Windows servers for OLTP workloads and Linux servers for reporting), you can now use Transaction Replication to synchronize data across them in real-time.

💡 Use Case Example:
A company runs its production SQL Server 2025 instance on Windows, but for cost efficiency, they use Linux servers for reporting. With Transaction Replication, changes made on the Windows Publisher are replicated instantly to the Linux Subscriber.

Key Components of Transaction Replication

1. Publisher 📰

   • The source database where transactions happen.

2. Distributor 📦

   • Manages replication flow and metadata.

3. Subscriber 📥

   • The database receiving replicated data (can now be Linux or Windows).

4. Log Reader Agent 🔎

   • Reads changes from the Publisher’s transaction log.

5. Distribution Agent 🚚

• Delivers transactions from Distributor to Subscriber.

How Transaction Replication Works in SQL Server 2025

1. Transaction Happens at Publisher
   Example: INSERT INTO Sales (ProductID, Amount) VALUES (101, 500)

2. Log Reader Agent Reads the Transaction
   Reads changes from the Publisher’s log.

3. Distributor Stores the Transaction
   Temporarily holds data for delivery.

4. Distribution Agent Applies Changes to Subscriber
   Updates the Subscriber database — even if it’s running on a different OS.

When to Use Transaction Replication

✅ For real-time reporting on a different platform (Windows → Linux).
✅ For hybrid environments where development runs on Linux but production on Windows.
✅ For low latency synchronization across distributed systems.
✅ When you want a read-only copy of your database for analytic

Advantages of Transaction Replication in SQL Server 2025

• ⚡ Near real-time updates

• 🔒 No locking on Publisher tables

• 🌍 Cross-platform replication between Windows and Linux

• 🎯 Granular control (specific tables/columns)

FAQs – Transaction Replication in SQL Server 2025

Q: What is Transaction Replication in SQL Server 2025?
A: Transaction Replication is a feature that copies data changes (inserts, updates, deletes) from one SQL Server database (Publisher) to another (Subscriber) in near real-time.

Q: Can SQL Server 2025 replicate data between Linux and Windows?
A: Yes. SQL Server 2025 now supports cross-platform replication. You can replicate data from a Windows server to a Linux server, from Linux to Windows, or even Linux to Linux.

Q: Why would I use Transaction Replication instead of backup/restore?
A: Backup/restore is a one-time operation. Transaction Replication continuously sends changes in real-time, keeping your Subscriber database up to date without manual effort.

Q: What are the main benefits of Transaction Replication in SQL Server 2025?
A:

• Real-time data updates

• Cross-platform support (Linux ↔ Windows)

• Minimal impact on the Publisher

• Multiple Subscribers supported

• Granular control over which tables or columns are replicated

Q: Is Transaction Replication good for bi-directional synchronization?
A: No. Transaction Replication is one-way (Publisher → Subscriber). If you need two-way synchronization, you should use Merge Replication or Peer-to-Peer Replication.