SQL Server Express and ARM
SQL Server Express is not included in the ARM installation package. If you choose the Express installation, the ARM installer downloads and installs SQL Server 2025 Express, including the appropriate pre-configuration. Installs on the automatic path will require internet access, while a manual path allows you to point to a pre-downloaded installer for servers without internet access.
Starting with ARM 2026.4, ARM supports SQL Server 2025 Express Edition (version 17.x). SQL Server 2025 Express supports databases of up to 50 GB. SQL Server 2022 Express and earlier versions support databases of up to 10 GB.
The following table lists the limitations with using SQL Server Express Edition for your ARM database.
| Limitation | Description |
|---|---|
| 50 GB maximum database size (SQL Server 2025 Express) 10 GB maximum database size (SQL Server 2022 Express and earlier) |
Stores a limited number of scans |
|
About 1.4 GB maximum memory for the buffer pool Microsoft's SQL Server Express Specification |
Provides poor performance in large environments |
|
Lesser of one socket or four cores maximum Microsoft's SQL Server Express Specification |
Provides poor performance in large environments |
When you set up your ARM database, use a full supported version of SQL Server running on an SQL database server.
See the system requirements for a list of supported SQL Server versions.
See the Microsoft Learn website for more information about SQL Server versions.
Optimizing your data storage
You can configure your ARM settings to optimize your data storage.
See Determine server thresholds for details about accessing Server Health Check. This utility allows you to review the current size of your ARM database.
See the following sections for details on how to reduce your ARM database size:
For more information about the capacity limits of each edition, see Editions and supported features of SQL Server 2025 on the Microsoft Learn website.