SQL Server 2025 vs SQL Server 2019: What’s New and Why It Matters
A lot of businesses are still running SQL Server 2019 quite happily. It was a strong release: better performance, better recovery, better security, and a big push into data virtualization and big-data workloads. But SQL Server 2025 is a very different kind of upgrade. Microsoft has moved the platform further toward AI, modern developer workflows, stronger default security, and more flexible hybrid operations.
The short version
SQL Server 2019 was about making the core engine smarter and faster, while also expanding into Big Data Clusters, PolyBase, UTF-8 support, Accelerated Database Recovery, and Always Encrypted with secure enclaves. SQL Server 2025 keeps building on performance and HA/DR, but the headline shift is AI and modern data development: vector data type, vector functions, vector indexes, regular expressions, native binary JSON support, REST endpoint invocation, change event streaming, TLS 1.3 with TDS 8.0, managed identity scenarios, and more capable Always On backup and secondary-read features.
Where SQL Server 2019 was strong
When SQL Server 2019 arrived, its big themes were performance, data platform breadth, and safer operations. It introduced Big Data Clusters with SQL Server, Spark, and HDFS on Kubernetes, plus PolyBase-based data virtualization across external data sources. It also added major engine improvements such as Intelligent Query Processing enhancements, batch mode on rowstore, APPROX_COUNT_DISTINCT, memory-optimized TempDB metadata, and Accelerated Database Recovery. On the security side, it expanded Always Encrypted with secure enclaves and added Data Discovery & Classification. For developers, 2019 added UTF-8 support, graph improvements, and Java language extensibility.
In other words, SQL Server 2019 was a very solid “database engine first” release. It helped existing workloads run better without demanding large code changes, which is one reason it has stayed popular. That’s an inference from Microsoft’s own feature emphasis on out-of-the-box performance, workload scalability, and minimal application changes.
What changes in SQL Server 2025
SQL Server 2025 is where the conversation changes. The platform now explicitly adds AI-oriented database capabilities. Microsoft’s official “What’s New” documentation highlights vector data type support, vector functions, vector indexes, external AI model objects, and AI-related T-SQL functions. It also adds GitHub Copilot integration in SSMS, which shows how the product is being positioned for AI-assisted operations and development rather than only traditional administration. Some of those capabilities, including vector indexes, are available through the PREVIEW_FEATURES database-scoped configuration and are intended to become fully available in later SQL Server 2025 updates.
That matters because SQL Server 2025 is no longer just a relational engine with a few smart tuning tricks. It is starting to support AI-adjacent use cases directly inside the platform, especially similarity search and embedding-driven workloads. That is a real shift from SQL Server 2019’s focus on big data and engine efficiency.
The biggest new features in SQL Server 2025
1. AI and vector search
This is the most obvious jump. SQL Server 2025 introduces a vector data type, vector functions, vector indexes, VECTOR_SEARCH, and model management for external AI inference endpoints. That gives SQL Server a native story for embeddings and similarity search, which simply was not part of SQL Server 2019.
2. More modern developer features
SQL Server 2025 adds regular expressions, fuzzy string matching, external REST/GraphQL endpoint invocation through sp_invoke_external_rest_endpoint, and JSON stored in a native binary format while still being queryable with built-in SQL functions and operators. Compared with SQL Server 2019’s developer story of UTF-8, graph, Java SDK, and extensibility, the 2025 release is much more focused on API-centric and AI-connected application patterns.
3. Stronger security defaults and connectivity
SQL Server 2025 adds TLS 1.3 with TDS 8.0 support in more places, PBKDF2-based password hashing by default, OAEP padding support for RSA operations, and managed identity options for several Azure-connected scenarios when SQL Server is Arc-enabled. This is a meaningful jump from SQL Server 2019, which already had strong features such as secure enclaves, but did not ship with these newer transport and credential-protection improvements.
4. Better HA/DR and readable-secondary operations
SQL Server 2025 brings several Always On improvements, including asynchronous page request dispatching improvements during failover recovery, configuration options around AG commit timing, contained distributed AG support, better diagnostics, and the ability to perform full and differential backups on any secondary replica in addition to copy-only backups. It also adds Query Store for readable secondaries by default and persisted statistics for readable secondaries. Compared with 2019, this makes 2025 much more attractive for organizations that actively use secondaries for reporting, backup offload, and higher operational efficiency.
5. Platform and Linux improvements
On Linux, SQL Server 2025 adds support for Ubuntu 24.04 and RHEL 10, enables TLS 1.3 by default, supports custom password policy on Linux, adds tempdb on tmpfs, and expands bulk import permissions and ODBC source support. SQL Server 2019 was already a meaningful Linux release with CDC support, non-root containers, and PolyBase on Linux, but 2025 clearly pushes Linux maturity further.
6. Edition changes that matter
SQL Server 2025 also changes the edition story. Standard edition now supports up to the lesser of 4 sockets or 32 cores and up to 256 GB buffer pool memory, compared with earlier versions’ 24-core and 128 GB Standard edition limits. Resource Governor is also available in Standard and Standard Developer editions, Express increases its max relational database size to 50 GB, and Web edition is discontinued.
So what is actually “new” compared with SQL Server 2019?
If you are upgrading directly from 2019, the practical new pieces are these:
SQL Server 2025 gives you native vector support, regex, fuzzy matching, binary JSON, REST endpoint invocation, event streaming, stronger modern encryption defaults, better managed-identity integration, broader readable-secondary usefulness, and a more generous Standard edition footprint. SQL Server 2019 did not have those capabilities in the form Microsoft now ships them.
Meanwhile, the things people loved in 2019, like ADR, IQP, PolyBase, UTF-8, and secure enclaves, are not the headline anymore. In 2025, they are part of a bigger platform story built around AI-readiness, hybrid connectivity, and secure-by-default operations. That framing is an inference from Microsoft’s published feature categories and release positioning.
A sensible way to think about the upgrade
If your environment is mostly stable OLTP and reporting, SQL Server 2019 is still a respectable platform. But if you want modern security defaults, richer secondary-replica usage, Linux currency, or an on-ramp to AI and vector-search style workloads without leaving SQL Server, SQL Server 2025 is a much more forward-looking release. That recommendation is an inference based on the feature deltas Microsoft documents between the two versions.
One caution before upgrading
SQL Server 2025 is not just “2019 plus extras.” It also introduces breaking changes tied to stronger encryption defaults. Microsoft documents upgrade risks around linked servers, replication with remote distributors, and remote log shipping monitoring unless trusted certificates and the new connectivity expectations are handled properly. Also, some 2025 features still rely on PREVIEW_FEATURES, so not every shiny feature is fully in the same maturity state yet.
Final take
SQL Server 2019 was about improving the traditional database engine and stretching into big data. SQL Server 2025 is about modernizing the platform for AI, stronger security defaults, hybrid cloud connectivity, and more capable operational patterns. If SQL Server 2019 felt like a very good database release, SQL Server 2025 feels like a broader data platform release. That final characterization is an inference from the feature sets Microsoft highlights for each version.