This SQL Server version brings AI into the engine itself: a vector type with vector indexes, external models, and AI_GENERATE_EMBEDDINGS. Native json and regular expression functions arrived with it too.
Read more: Microsoft Learn
In the Ultra Transcenders books
Each book explains SQL Server 2025 in context, with comparison tables and the common traps.
Terms in this definition
- SQL Server
The relational database from Microsoft that organisations host and run themselves, in their own data centres or on VMs. Its engine also sits underneath the Azure SQL services and SQL database in Fabric.
- External
API Management virtual network mode in which the gateway stays public but can call private back ends inside the VNet.
- Field generation method
How a Content Understanding schema field is filled: extract takes the value as written (documents only), classify chooses from categories, and generate infers or summarises it.
- Embeddings
Vectors of numbers encoding what text means, placing related content close together as judged by cosine similarity. Switching model or vector size requires embedding all content again.
- JSON
Text-based format for structured data. ARM templates and Cosmos DB documents are written in it, and most Azure REST APIs exchange request and response bodies as application/json.
- Regular expression functions
Built into T-SQL in SQL Server 2025, Azure SQL and SQL database in Fabric, and based on RE2, these let you match, validate, extract and replace text by pattern. The set comprises REGEXP_LIKE, REGEXP_COUNT, REGEXP_INSTR, REGEXP_SUBSTR, REGEXP_REPLACE, REGEXP_MATCHES and REGEXP_SPLIT_TO_TABLE.
Related terms
- ASSUME_FIXED_MAX_SELECTIVITY_FOR_REGEXP
A query hint for SQL Server 2025 and Azure SQL Database that gives
REGEXP_LIKEa fixed, higher selectivity, for cases where the normal cardinality estimate comes out too low. - ASSUME_FIXED_MIN_SELECTIVITY_FOR_REGEXP
A query hint for SQL Server 2025 and Azure SQL Database that gives
REGEXP_LIKEa fixed, lower selectivity, for cases where the normal cardinality estimate comes out too high. - CES
Sends every row change in a stream group's tables to Fabric Eventstream or Azure Event Hubs, each as a CloudEvent. It's in preview for SQL database in Fabric, Managed Instance, Azure SQL Database and SQL Server 2025; delivery over AMQP was deprecated on 15 August 2026, with Kafka the recommended route.
- DSP
A property in a SQL project (.sqlproj), which names the platform being targeted, such as Azure SQL Database or SQL Server 2025. Builds check syntax against that platform, and publishing fails if the target doesn't match.
- Fuzzy string matching
Measuring how far apart two strings are instead of whether they are identical, through EDIT_DISTANCE, JARO_WINKLER and their _SIMILARITY variants. The functions are still in preview and need PREVIEW_FEATURES enabled on SQL Server 2025.
- ONNX Runtime
An open-source engine for running ONNX models on the machine itself. When installed on Windows, SQL Server 2025 points an external model at it with LOCAL_RUNTIME_PATH, so embeddings are created with nothing remote involved.
- PREVIEW_FEATURES
Turning this database scoped configuration ON gives access to SQL Server 2025 preview features, among them the fuzzy string matching functions.
- SSRS
SQL Server Reporting Services. Used on premises to create, deploy and manage paginated reports, it has been consolidated, from SQL Server 2025 onwards, into Power BI Report Server for on-premises reporting.