Microsoft has officially lifted the curtain on SQL Server 2025, and it is shaping up to be one of the most significant releases in years. Rather than just another incremental update, this version brings transformative features around AI, hybrid analytics, performance, and security. In this post, we’ll walk through the highlights of SQL Server 2025 and what they mean for developers and DBAs.

AI and Vector Integration

The headline feature in SQL Server 2025 is its native support for vectors. For the first time, you can store and query vector embeddings directly inside SQL Server. The database now includes optimized binary storage, vector functions, and a new index type designed specifically for similarity searches (Microsoft Docs).

On top of that, new T-SQL capabilities such as AI_GENERATE_CHUNKS can process and chunk text into embeddings without leaving the database. Developers can also host external AI models using CREATE EXTERNAL MODEL with ONNX support, or call out to AI services (such as Azure OpenAI) directly via the new stored procedure sp_invoke_external_rest_endpoint (Brent Ozar).

This means SQL Server is no longer just the place where your data resides – it is becoming part of the AI workflow itself.

Regular Expressions in T-SQL

One of the most requested developer features has finally landed: native regex support. SQL Server 2025 adds REGEXP_REPLACE, REGEXP_SUBSTR, and REGEXP_LIKE, and importantly, these functions are SARGable. That means they can use indexes, rather than forcing scans, which makes pattern-matching queries more efficient than ever before (Microsoft Docs).

Real-Time Event Streaming and Fabric Integration

Another standout addition is Change Event Streaming (CES). SQL Server can now stream changes in near real time to systems like Azure Event Hubs or Kafka, removing the need for custom ETL pipelines (MSSQLTips).

For analytics, Fabric Mirroring lets OLTP data flow directly into Microsoft Fabric, enabling reporting and analysis without traditional extract-transform-load processes. This tight integration blurs the line between transactional and analytical workloads, allowing organizations to run operational and analytical queries side by side (Microsoft Blog).

Performance and Intelligent Query Processing

SQL Server 2025 continues Microsoft’s focus on high-performance query execution. New locking strategies like Transaction ID (TID) locking and Lock-After-Qualification (LAQ) reduce blocking and improve concurrency under heavy workloads (Microsoft Blog).

Intelligent Query Processing (IQP) has also been expanded, with improvements in cardinality estimation, parameter plan optimization, Query Store integration with readable secondaries, and DOP feedback (Cegal). Other notable engine improvements include:

• Accelerated Database Recovery (ADR) extended to TempDB
• ZSTD backup compression for smaller backups and faster restores
• Expression cache persistence to reduce recompilations
• Optimized execution for sp_executesql (MSSQLTips)

Security Enhancements

SQL Server 2025 raises the bar on security. It fully supports TLS 1.3 and the new TDS 8.0 protocol across replication, Availability Groups, Linked Servers, and Log Shipping. By default, more communication paths now require encryption, reducing the risk of accidental misconfiguration (Microsoft Docs).

Integration with Microsoft Entra (Azure AD) enables managed identities for seamless service authentication, removing the need to manage passwords in many cases. SQL Server also now uses PBKDF-based password hashing aligned with modern NIST guidelines, and Linux installations can enforce custom password policies (MSSQLTips).

Developer Experience

Beyond engine features, Microsoft is paying attention to the developer experience. SQL Server Management Studio 21 is now 64-bit, includes Git integration, and has a Copilot preview that can generate queries, explain plans, and even suggest performance improvements (Microsoft Blog).

For development environments, two flavours of Developer Edition are available for the first time: a Standard Developer Edition and an Enterprise Developer Edition. This ensures teams can build and test against the same feature set they will deploy to in production (Microsoft Docs).

Deprecations and Retired Features

Not everything makes it into the future. SQL Server 2025 retires Master Data Services (MDS) and Data Quality Services (DQS), as well as Synapse Link and Purview access policies. Even hot-add CPU support has been deprecated. Reporting Services is being consolidated into Power BI Report Server going forward (Microsoft Docs).

Final Thoughts

SQL Server 2025 is more than an incremental upgrade. It positions SQL Server as an AI-ready, cloud-integrated database that serves as much more than a storage engine. With vectors, regex, event streaming, Fabric integration, and Copilot-powered tooling, Microsoft is signaling that the database is not just where your data lives – it’s where intelligence begins.

For DBAs, the focus will be on exploring new performance and security defaults. For developers, it will be about rethinking workflows: using regex in queries, calling REST APIs from T-SQL, or building applications that rely on vector search inside SQL Server.

Thanks for your time,

-Klaus