SQL Server vs Oracle: Licensing, Editions and SQL (2026)

Quick verdict

Short answer

Choose SQL Server if you work in a Microsoft environment, write T-SQL, and want HA, partitioning and in-memory features included in the edition price rather than bought as add-ons. Choose Oracle AI Database if you run Oracle applications, need capabilities such as Real Application Clusters, or already have Oracle skills and licences, and are prepared to license options and packs separately. For a new project with no existing commitment to either, price both carefully, and consider PostgreSQL as well.

How we know: This comparison is research-based: releases, editions, licensing and prices were checked against Microsoft Learn, Microsoft's SQL Server 2025 pricing sheet, Oracle's AI Database FAQ, the Oracle AI Database 26ai documentation and licensing information manual, and the Oracle Technology Global Price List (15 September 2026) in October 2026. We have not run performance tests, and nothing here is a benchmark.

SQL Server is Microsoft's relational database. The current release is SQL Server 2025 (17.x), at Cumulative Update 9 when we checked. Paid editions are Enterprise and Standard; Express is free and usable in production within resource limits, and the free Developer editions (Standard Developer and Enterprise Developer) are for development and test only. It runs on Windows and on Red Hat Enterprise Linux 9 and 10 and Ubuntu 22.04 and 24.04.

Oracle AI Database is Oracle's current name for Oracle Database. Oracle describes Oracle AI Database 26ai as a long-term support release that replaces Oracle Database 23ai: customers move from 23ai to 26ai by applying the October 2025 release update, and Oracle says it supersedes 19c as the long-term release. Oracle states that a long-term release gets five years of Premier Support and three years of Extended Support. Releases are delivered as quarterly release updates numbered 23.26.x. The free edition is Oracle AI Database Free.

Both are mature, ACID compliant engines used for large production systems. This page focuses on what differs: editions and licensing, platforms, concurrency, high availability, and the SQL dialect.

Side by side

Aspect	SQL Server	Oracle
Current release	SQL Server 2025 (17.x)	Oracle AI Database 26ai (release updates 23.26.x); 19c is the previous long-term release
Free edition	Express: 50 GB per database, 1,410 MB buffer pool, lesser of 1 socket or 4 cores; Developer for non-production	Oracle AI Database Free: 2 cores, 2 GB RAM, 12 GB user data, one installation per host
Paid editions	Standard and Enterprise	Enterprise Edition; Standard Edition 2 listed for 26ai on Oracle Database Appliance
Licence metrics	Per core (2-core packs), or Server + CAL for Standard; subscriptions and pay-as-you-go via Azure Arc	Processor (core factor table; SE2 counts sockets) or Named User Plus
Add-on licensing	Features are included per edition	Many Enterprise Edition features are extra-cost options and packs (RAC, Partitioning, In-Memory, Active Data Guard, Diagnostics and Tuning Packs)
Server platforms	Windows; RHEL 9 and 10, Ubuntu 22.04 and 24.04	26ai on-premises Enterprise Edition listed for Linux x86-64; Free on Linux x86-64, Arm Linux and Windows
Procedural language	Transact-SQL (T-SQL)	PL/SQL
Default concurrency	READ COMMITTED with shared locks; row versioning via READ_COMMITTED_SNAPSHOT or SNAPSHOT	Multiversion read consistency: queries do not block writers by default
Scale-out HA	Always On availability groups (Enterprise), failover cluster instances	Real Application Clusters and Active Data Guard (both extra-cost options for Enterprise Edition)
Managed cloud	Azure SQL Database, Azure SQL Managed Instance, Amazon RDS, Google Cloud SQL	Oracle Autonomous AI Database and other database services on Oracle Cloud Infrastructure (OCI)
Main trade-off	Licence cost scales with cores; full AGs need Enterprise	Base licence plus options can multiply the cost; licensing rules are complex

Key differences

Editions and how features are licensed

SQL Server sells features by edition: once you pay for Enterprise, partitioning, in-memory OLTP, availability groups and other engine features are included. Standard includes most programmability features with caps on cores and memory, and basic availability groups. See SQL Server Standard vs Enterprise and Express vs Standard.

Oracle sells a base edition and then options and packs. Oracle's 26ai licensing information manual lists Oracle Real Application Clusters, Partitioning, Database In-Memory, Active Data Guard, Advanced Compression, Advanced Security, Database Vault and Multitenant (beyond the included PDBs) as extra-cost options for Enterprise Edition, and the Diagnostics and Tuning Packs as separately licensed management packs. For 26ai the manual lists Standard Edition 2 as SE2-ODA, installed on Oracle Database Appliance, with up to 3 pluggable databases. Confirm with Oracle which editions are available for your hardware before planning, because the edition and platform matrix for 26ai differs from 19c.

Free editions compared

SQL Server 2025 Express is free for production use, limited to the lesser of 1 socket or 4 cores, 1,410 MB of buffer pool memory and 50 GB per database, with no SQL Server Agent. Developer editions have the full feature set of Standard or Enterprise but are licensed only for development and test. See SQL Server Express vs Developer.

Oracle AI Database Free is released under the Oracle Free Use Terms and Conditions. Its documented restrictions are 2 cores, 2 GB of RAM, 12 GB of user data (exceeding it raises ORA-12954) and one installation per host or VM. Oracle offers it as an RPM, a container image, a VirtualBox VM and on Windows. Oracle also points to the Autonomous AI Database Free Tier on OCI for trying 26ai in the cloud.

SQL dialect: T-SQL and Oracle SQL side by side

Core SQL is similar; the differences are in row limiting, auto-numbering, string aggregation and procedural code. Examples target SQL Server 2017 or later and Oracle Database 12c or later unless stated.

First 10 rows

-- SQL Server (T-SQL)
SELECT TOP (10) id, name FROM customers ORDER BY name;
-- standard form, also accepted by SQL Server
SELECT id, name FROM customers ORDER BY name
OFFSET 0 ROWS FETCH NEXT 10 ROWS ONLY;

-- Oracle (12c and later)
SELECT id, name FROM customers ORDER BY name
FETCH FIRST 10 ROWS ONLY;

Auto-numbered key. Oracle supports identity columns from 12c; before that, and still commonly, a sequence supplies the value. SQL Server also has sequences.

-- SQL Server (T-SQL)
CREATE TABLE orders (
  id INT IDENTITY(1,1) PRIMARY KEY,
  total DECIMAL(10,2) NOT NULL
);

-- Oracle (12c and later)
CREATE TABLE orders (
  id NUMBER GENERATED ALWAYS AS IDENTITY PRIMARY KEY,
  total NUMBER(10,2) NOT NULL
);

-- Oracle, with a sequence
CREATE SEQUENCE orders_seq;
INSERT INTO orders_legacy (id, total) VALUES (orders_seq.NEXTVAL, 99.50);

Comma separated list per group. SQL Server uses STRING_AGG (2017 and later); Oracle uses LISTAGG. The ordering clause looks the same.

-- SQL Server (T-SQL)
SELECT dept, STRING_AGG(name, ', ') WITHIN GROUP (ORDER BY name) AS staff
FROM employees GROUP BY dept;

-- Oracle
SELECT dept, LISTAGG(name, ', ') WITHIN GROUP (ORDER BY name) AS staff
FROM employees GROUP BY dept;

Other differences to plan for: Oracle treats an empty string as NULL, SQL Server does not; Oracle's VARCHAR2 and NUMBER map to SQL Server's varchar/nvarchar and decimal/int types. Oracle AI Database (23ai and 26ai) added a SQL BOOLEAN type and SELECT without a FROM clause (no more FROM DUAL for expressions), which SQL Server has long allowed for SELECT. Procedural code is the biggest job: T-SQL batches and TRY...CATCH versus PL/SQL blocks, packages and exception handlers. Expect to rewrite stored procedures in either direction. Our SQL functions library covers T-SQL functions.

Concurrency model

Oracle uses multiversion read consistency for every query: readers see a consistent snapshot built from undo data, so queries do not wait for writers and writers do not wait for queries. SQL Server's default READ COMMITTED level uses shared locks on SQL Server (Azure SQL Database turns on READ_COMMITTED_SNAPSHOT by default). Enabling READ_COMMITTED_SNAPSHOT or using SNAPSHOT isolation gives SQL Server similar reader behaviour using row versions in tempdb. Teams moving from Oracle to SQL Server should decide on this setting early.

High availability, tooling and cloud

SQL Server's HA is in the edition: Always On availability groups with multiple readable secondaries in Enterprise, basic availability groups in Standard, and failover cluster instances. Oracle's distinctive option is Real Application Clusters, where several servers open the same database at once It and Active Data Guard are extra-cost options for Enterprise Edition, according to Oracle's licensing manual.

For tools, Microsoft provides SSMS (Windows) and the MSSQL extension for VS Code. Oracle provides SQL Developer, and third-party tools such as Toad, DBeaver and DataGrip support both engines. In the cloud, SQL Server maps to Azure SQL Database and Managed Instance (see Azure SQL Database vs SQL Server); Oracle's managed offering is Autonomous AI Database on OCI.

Pricing and licensing

SQL Server 2025. Listed on Microsoft's pricing sheet in October 2026, in US dollars, as open no-level estimated retail prices (your reseller price may differ): Enterprise USD 15,123 per 2-core pack; Standard USD 3,945 per 2-core pack, or USD 989 per server plus USD 230 per CAL. Volume licensing subscriptions are listed at USD 5,434 per year (Enterprise) and USD 1,418 per year (Standard) per 2-core pack. Express and Developer are free.

Oracle AI Database. Listed on the Oracle Technology Global Price List dated 15 September 2026, in US dollars, perpetual licence plus first-year Software Update License and Support: Enterprise Edition USD 47,500 per Processor (support USD 10,450) or USD 950 per Named User Plus (support USD 209); Standard Edition 2 USD 17,500 per Processor (support USD 3,850) or USD 350 per Named User Plus (support USD 77). Options are added on top, for example Real Application Clusters USD 23,000, Partitioning USD 11,500, Active Data Guard USD 11,500 and Database In-Memory USD 23,000 per Processor. For Enterprise Edition, the number of Processor licences is the core count multiplied by Oracle's core factor; for Standard Edition 2 a processor is counted as an occupied socket. Named User Plus licences are subject to minimums. Oracle AI Database Free costs nothing.

The two price lists use different metrics, so convert both to your actual core count, users and required features before comparing. Neither list includes discounts, and Oracle support is charged annually.

Pricing checked on the vendors' official pages on 7 October 2026. Prices change; confirm before buying.

Where each one leads

SQL Server strengths

Edition-based licensing: partitioning, in-memory and availability groups are included in Enterprise with no option fees
Free Express edition usable in production, and full-featured Developer editions for dev and test
SQL Server 2025 adds native json and vector data types and regular expression functions
First-party tooling (SSMS, SQL Server Agent, Query Store) and a direct path to Azure SQL

Oracle strengths

Real Application Clusters for active-active clustering of one database across servers
Multiversion read consistency by default, so queries do not block writers
Long-term support releases with five years of Premier Support plus three of Extended Support
Mature PL/SQL with packages, and deep integration with Oracle applications and Exadata
Oracle AI Database Free, plus an Autonomous AI Database free tier on OCI, for learning

Limitations

SQL Server limitations

Express is capped at 50 GB per database, 1,410 MB buffer pool and 4 cores, with no SQL Server Agent
Per-core licensing makes large servers expensive; full availability groups need Enterprise
No native macOS server, and SSMS runs on Windows only
READ COMMITTED uses locking by default unless row versioning is enabled

Oracle limitations

Many Enterprise Edition features are separately priced options and packs, which makes cost hard to estimate
For 26ai, Oracle lists Standard Edition 2 only on Oracle Database Appliance, narrowing the lower-cost route
Oracle AI Database Free is limited to 2 cores, 2 GB RAM and 12 GB of user data
Licensing rules (core factors, Named User Plus minimums, virtualisation) are complex and audited

When to choose each

Choose SQL Server if

Your organisation runs on Windows Server, .NET, Active Directory or Azure
You want HA and advanced engine features included in the edition rather than bought as options
Your workload fits Express, or you want a supported path to Azure SQL Database or Managed Instance
Your team already writes T-SQL and uses SSMS

Choose Oracle if

You run Oracle E-Business Suite or other applications certified on Oracle Database
You need active-active clustering of one database with Real Application Clusters
Your team has PL/SQL code and Oracle DBA skills that would be costly to replace
You are standardising on OCI and Autonomous AI Database

When neither is right

You want no licence fees at any scale: PostgreSQL is the usual open source alternative. See SQL Server vs PostgreSQL and PostgreSQL vs Oracle.
Your stack is web hosting and PHP where MySQL is the default: see MySQL vs SQL Server and MySQL vs Oracle.
Your data is mostly flexible documents rather than tables: see MongoDB vs SQL Server and MongoDB vs PostgreSQL.

Final recommendation

Bottom line

Neither engine wins outright. SQL Server is usually simpler to license and budget, because features come with the edition, and it is the natural fit for Microsoft environments and for a later move to Azure SQL. Oracle AI Database makes sense when Oracle applications, RAC or existing PL/SQL and Oracle skills tie you to it; budget for the options and packs you actually need, and check which editions 26ai offers on your platform. Prototype on the free editions (Express or Developer, and Oracle AI Database Free), then price the production configuration from each vendor's list before deciding.

Frequently asked questions

What is the latest version of Oracle Database?

Oracle now calls the product Oracle AI Database. The current release is Oracle AI Database 26ai, a long-term support release that replaced 23ai through the October 2025 release update; updates are numbered 23.26.x. Oracle Database 19c is the previous long-term release.

Is Oracle more expensive than SQL Server?

On list prices, Oracle Enterprise Edition is USD 47,500 per Processor licence plus annual support, with options such as RAC or Partitioning added on top, while SQL Server 2025 Enterprise is USD 15,123 per 2-core pack. The metrics differ (Oracle applies a core factor), so compare on your own core count and feature list. See the dated pricing section above.

Is there a free version of Oracle Database?

Yes. Oracle AI Database Free is available for Linux x86-64, Arm Linux and Windows under the Oracle Free Use Terms, limited to 2 cores, 2 GB of RAM and 12 GB of user data. SQL Server's free editions are Express (production use, with limits) and Developer (non-production).

Is T-SQL very different from PL/SQL?

Plain queries are similar, but row limiting (TOP vs FETCH FIRST), string aggregation (STRING_AGG vs LISTAGG), empty-string handling and especially procedural code differ. Stored procedures, packages and error handling need rewriting when you move between them.

Does SQL Server have an equivalent to Oracle RAC?

Not exactly. SQL Server availability groups replicate databases to secondary replicas, which can serve reads, but only the primary accepts writes. Oracle RAC lets several servers open and write to the same database. RAC is an extra-cost option for Oracle Enterprise Edition.

Sources

Checked October 2026.

How we research comparisons: our editorial method.