SQL Sync, commonly known as SQL Data Sync, is a powerful cloud-based service designed to address data synchronization needs across various database locations.
At its core, as stated in the reference, SQL Data Sync is a service built on Azure SQL Database that lets you synchronize the data you select bi-directionally across multiple databases, both on-premises and in the cloud. (Reference: 23-Sept-2024)
Understanding SQL Data Sync
This service acts as a data synchronization engine, allowing you to keep data consistent between different SQL databases. Whether your databases are located within Azure SQL Database in the cloud or in SQL Server databases running on your own premises, SQL Data Sync facilitates the movement and reconciliation of data changes.
Key aspects of SQL Data Sync include:
- Bi-directional Synchronization: Data can be synced in both directions, meaning changes made in one database can be propagated to others, and vice-versa.
- Data Selection: You have control over which tables and rows are included in the synchronization process, allowing for flexibility and targeted data movement.
- Topology: SQL Data Sync uses a hub-and-spoke model. One database is designated as the hub database, and all other databases (cloud or on-premises) are members of the sync group. Synchronization occurs between the hub and individual members.
- Use Cases: It's typically used for scenarios like:
- Distributing data across distributed applications.
- Enabling offline applications with data caching.
- Synchronizing data between databases in different Azure regions or between Azure and on-premises environments.
How it Works
The service operates by creating a sync group, which defines:
- The hub database.
- The member databases.
- The synchronization direction (Hub to Member, Member to Hub, or Bi-directional).
- The schema of the tables to be synchronized.
- The synchronization schedule.
SQL Data Sync uses a background process to track changes, record them in side tables, and then synchronize those changes according to the defined schedule and direction.
In summary, SQL Data Sync simplifies the complex task of keeping data consistent across dispersed SQL Server and Azure SQL databases, providing a robust solution for various data distribution and caching requirements.
