SQL Server 2025 is Microsoft's flagship relational database management system (RDBMS), a comprehensive platform for enterprise data storage, processing, and analytics that runs on both Windows and Linux. This release, generally available since November 2025, introduces transformative capabilities including native AI integration with vector search and DiskANN indexing, a native JSON data type with binary storage and indexing, regular expression functions, and significant performance improvements through intelligent query processing. Understanding SQL Server's rich feature set—from core T-SQL syntax and indexing strategies to advanced capabilities like temporal tables, Always On availability, and in-memory OLTP—is essential for building scalable, high-performance database solutions.
What This Cheat Sheet Covers
This topic spans 33 focused tables and 290 indexed concepts. Below is a complete table-by-table outline of this topic, spanning foundational concepts through advanced details.
Table 1: Core Data Types
| Type | Example | Description |
|---|---|---|
product_id INT | • Standard 4-byte integer ranging from -2,147,483,648 to 2,147,483,647 • the most common whole number type. | |
order_total BIGINT | 8-byte integer supporting extremely large values (-9,223,372,036,854,775,808 to 9,223,372,036,854,775,807). | |
name VARCHAR(100) | • Variable-length string storing up to n characters (max 8,000)• uses only space needed plus 2 bytes overhead. | |
title NVARCHAR(200) | • Unicode variable-length string supporting international characters • 2 bytes per character, max 4,000 characters. | |
price DECIMAL(10,2) | • Fixed-precision numeric where p is total digits (1-38) and s is decimal places• essential for financial data. | |
created_at DATETIME2 | • High-precision datetime with 100-nanosecond accuracy • range 0001-01-01 to 9999-12-31 • recommended over legacy DATETIME. | |
birth_date DATE | • Date-only type (no time component) storing YYYY-MM-DD • 3 bytes storage. |