Azure SQL Database Compute Reference
This document provides detailed information about the compute options available for Azure SQL Database, helping you select the most suitable configuration for your workload.
Compute Models
Azure SQL Database offers two primary compute models for relational databases:
- Managed Instance: Provides near 100% compatibility with on-premises SQL Server, making it ideal for lift-and-shift migrations with minimal application changes.
- Single Database: A fully managed PaaS database engine that handles most database management functions without the administrator needing to involve a deep level of expertise.
Service Tiers and Hardware Generations
Azure SQL Database offers various service tiers and hardware generations to meet different performance and cost requirements. The key tiers are:
General Purpose
Designed for most common workloads. Offers a balance of cost and performance.
| Hardware Generation | vCore Options | Memory per vCore | Max Data Size | IOPS & Throughput |
|---|---|---|---|---|
| Gen5 | 2, 4, 8, 16, 24, 32, 40, 64, 80 | ~4 GB | Up to 1 TB | See Azure documentation for specifics |
| Standard_Dbs_v2 | 2, 4, 8, 16, 24, 32, 40, 64, 80 | ~4 GB | Up to 1 TB | See Azure documentation for specifics |
Business Critical
Designed for high-performance, low-latency applications and workloads that require fast data recovery.
| Hardware Generation | vCore Options | Memory per vCore | Max Data Size | IOPS & Throughput |
|---|---|---|---|---|
| Gen5 | 4, 8, 16, 24, 32, 40, 64, 80 | ~8 GB | Up to 1 TB | Higher than General Purpose |
| Standard_Dbs_v2 | 4, 8, 16, 24, 32, 40, 64, 80 | ~8 GB | Up to 1 TB | Higher than General Purpose |
Hyperscale
Offers highly scalable storage and compute, designed for large databases.
| vCore Options | Max Data Size | Compute Options |
|---|---|---|
| 1, 2, 4, 8, 16, 24, 32, 40, 48, 56, 64, 72, 80, 88, 96, 104, 112, 120, 128, 136, 144, 152, 160, 168, 176, 184, 192, 200 | Up to 100 TB | Standard, Memory Optimized |
vCore Purchasing Models
Azure SQL Database offers two purchasing models for vCores:
- DTU (Database Transaction Unit): A bundled measure of compute, memory, and I/O resources. Simpler to understand for basic workloads.
- vCore: Offers explicit control over the number of vCores, memory, and I/O. Recommended for most production workloads.
Managed Instance Compute Options
Azure SQL Managed Instance offers similar compute options to SQL Server, with different service tiers:
- General Purpose: Provides a balanced compute and storage capacity.
- Business Critical: Offers high availability and low-latency storage for demanding applications.
For Managed Instance, you select the number of vCores and the amount of storage. The memory is allocated based on the vCore selection.
Note on Hardware Generations
Azure continuously updates its hardware. Newer hardware generations typically offer improved performance and efficiency. Always refer to the official Azure documentation for the most up-to-date hardware availability and specifications.
Performance Tuning Tip
For optimal performance, consider the characteristics of your workload. Read-heavy workloads may benefit from Business Critical, while mixed workloads can often run well on General Purpose. Hyperscale is ideal for very large datasets and fluctuating demands.
Important Considerations
When choosing compute options, factor in current and projected resource needs, budget constraints, and your application's performance requirements. It's recommended to start with a baseline configuration and scale as needed.