Overview
ISO/IEC 9075-2:2023/Cor 1:2026 is the first technical corrigendum to ISO/IEC 9075-2:2023, the international standard for Information Technology - Database Languages SQL - Part 2: Foundation (SQL/Foundation). Published by ISO and IEC, this corrigendum clarifies, corrects, and updates key elements of the SQL Foundation specifications, ensuring alignment with current best practices and resolving inconsistencies detected after the 2023 edition's release.
This technical corrigendum is essential for database software vendors, implementers, and organizations relying on SQL standards for database management, interoperability, and data integrity. By adopting the corrections and clarifications specified in this document, users can facilitate consistent database implementations and future-proof their SQL-based solutions.
Key Topics
- Enhanced Nullability Determination: The corrigendum specifies and clarifies how SQL implementations should identify and manage nullability, particularly where Feature T101 “Enhanced nullability determination” is supported, reducing duplication and confusion.
- Grouped Tables and Data Analysis: Corrections are provided to definitions and operations related to grouped tables (resultant from GROUP BY clauses) and group functions to address prior over-restriction and potential ambiguities.
- Lexical and Syntax Elements: Updates the treatment of whitespace, token definitions, and identifiers for more precise syntax interpretation and conformance rules, especially regarding implementation-defined whitespace handling.
- Value Functions and Expressions: Refines definitions and result types for SQL value functions (numeric, string, JSON) and case expressions, ensuring correct handling of types, exception conditions, and compatibility with existing and emerging features.
- Predicates and Conformance: Provides corrected conformance requirements for SQL language features, clarifying which feature sets are mandatory or optional for SQL implementations, especially for advanced predicate support (e.g., LIKE, SIMILAR, REGEX).
- Aggregate and Window Functions: Rectifies formula representations and exception handling within SQL aggregate and windowing functions for consistent and reliable operations.
- Feature Relationships and Mandatory Requirements: Updates and removes implied feature relationships and taxonomy entries to better reflect the foundation and modular adoption of SQL features across implementations.
- Incompatibilities and Migration Notes: Identifies changes that may impact compatibility with earlier editions, ensuring implementers are aware of modified exception conditions and other critical adjustments.
Applications
ISO/IEC 9075-2:2023/Cor 1:2026 serves organizations and professionals involved in the development, deployment, or migration of SQL-compatible database systems. Its applications include:
- Database Software Development: Ensures database management systems and SQL engines accurately reflect the latest standard interpretations and corrections, fostering robust and interoperable solutions.
- Enterprise Data Management: Assists enterprise architects, DBAs, and data integrators in maintaining compliance with current SQL Foundation standards, enhancing data integrity, and minimizing vendor lock-in.
- Quality Assurance & Conformance Testing: Provides a reference for SQL conformance test suites, enabling validation that database products meet revised requirements and handle data and operations as standardized.
- Interoperability and Migration Planning: Aids in assessing and planning migration paths for databases transitioning from earlier SQL standards to the 2023 foundation, taking into account all technical corrections to avoid pitfalls.
Related Standards
- ISO/IEC 9075-1: Framework for SQL - Database languages (General concepts).
- ISO/IEC 9075-2:2023: Information technology - Database languages SQL - Part 2: Foundation (SQL/Foundation).
- ISO/IEC 9075-4: SQL – Part 4: Persistent Stored Modules (SQL/PSM).
- ISO/IEC 9075-11: SQL/Management of External Data (SQL/MED).
- Other Technical Corrigenda: Corrections to related SQL parts improving cross-part consistency.
Implementing ISO/IEC 9075-2:2023/Cor 1:2026 is a strategic step for organizations seeking to maintain state-of-the-art SQL compliance and build database solutions that are robust, interoperable, and ready for the future. For more information and to access the full standard, visit iso.org.