ISO/IEC 9075

ISO/IEC 9075
Title	ISO/IEC 9075
Status	Published
Started	1986
Organization	International Organization for Standardization and International Electrotechnical Commission
Domain	Information technology
Related	Structured Query Language, ISO/IEC 11770, SQL:1999

ISO/IEC 9075 is the international standard that specifies the Structured Query Language used for managing and querying relational database management systems. The standard defines syntax, semantics, data types, integrity constraints, and interfaces for SQL across multiple parts, providing a basis for interoperability among implementations such as Oracle Corporation products, Microsoft SQL Server, PostgreSQL, and IBM Db2. ISO/IEC 9075 is maintained jointly by ISO and IEC technical committees and has influenced standards and implementations in commercial, academic, and open source ecosystems including MySQL, SQLite, SAP SE, and Amazon Aurora.

Overview

ISO/IEC 9075 codifies core aspects of Structured Query Language and related features to support data definition, data manipulation, transaction control, and security. The standard addresses relationships among relational model constructs originally articulated by Edgar F. Codd and integrates features from successive SQL revisions such as those in SQL:1999, SQL:2003, and SQL:2016. It provides normative language for vendors like Oracle Corporation, Microsoft Corporation, IBM, and SAP SE to implement compliant functionality used by applications developed by organizations including Facebook, Google, Twitter, Netflix, and Stripe.

Parts and Structure

ISO/IEC 9075 is modular, composed of multiple parts that separate core requirements from optional extensions. Key parts include the core language, called Parts 1–4 in early editions and expanded in later editions to cover bindings, persistent stored modules, XML-related features, and security semantics. These parts align with concepts introduced by pioneers such as Donald D. Chamberlin and Raymond F. Boyce and intersect with standards like ISO/IEC 11770 on authentication. Implementations by vendors such as Oracle Corporation, Microsoft Corporation, and IBM may claim conformance to specific parts or options, while open source systems like PostgreSQL, MariaDB, and SQLite selectively implement subsets.

History and Development

The development trajectory of ISO/IEC 9075 traces to the late 1970s and 1980s when IBM research and academic work culminated in the original SQL language. Early standardization efforts involved organizations including ANSI and ISO, with committees drawing expertise from companies such as Ingres Corporation and institutions like University of California, Berkeley. Major revisions occurred with milestones like SQL:1992 and SQL:1999 introducing object-relational features and procedural extensions influenced by work from Michael Stonebraker and others. Subsequent editions reflected contributions from vendors and consortia including Oracle Corporation, Microsoft Corporation, IBM, SAP SE, and open source communities around PostgreSQL and MySQL.

Relationship to SQL Standards and Implementations

ISO/IEC 9075 both defines and interacts with other standards and implementations. It corresponds with ANSI SQL standards and informs database products from Oracle Corporation, Microsoft Corporation, IBM, AWS, and SAP SE. Open source implementations such as PostgreSQL, MySQL, and SQLite reference the standard for compatibility while also incorporating extensions used by platforms like Heroku, Google Cloud Platform, and Microsoft Azure. The standard influences application stacks built with frameworks from Django Software Foundation, Ruby on Rails, and Spring Framework, and is reflected in query optimizers developed at institutions like Massachusetts Institute of Technology and Stanford University.

Conformance and Certification

Conformance to ISO/IEC 9075 is typically declared by vendors and may be verified by conformance test suites and interoperability tests developed by standards committees and industry groups. Organizations such as ISO and IEC coordinate technical reports and profiles that third parties use to evaluate implementations from Oracle Corporation, Microsoft Corporation, IBM, PostgreSQL Global Development Group, and others. Certification programs and compliance claims are often used in procurement by enterprises like Goldman Sachs, JP Morgan Chase, and Walmart seeking assured behavior for transactional and analytical workloads. Test harnesses and reference implementations from academic consortia and companies help assess adherence to parts and optional features.

Extensions and Related Specifications

Numerous extensions and related specifications build on ISO/IEC 9075, including standard parts addressing XML integration, procedural languages, and persistent stored modules. Related specifications and technologies include XQuery, XPath, and data modeling work from W3C; security and identity standards from OASIS; and cloud data services by Amazon Web Services, Google Cloud Platform, and Microsoft Azure. Commercial extensions by Oracle Corporation, Microsoft Corporation, and IBM often implement non‑standard features that have become de facto when adopted by ecosystems like Salesforce or SAP SE.

Criticism and Revisions

Critiques of the standard have focused on perceived complexity, slow revision cycles, and optional features leading to fragmentation among vendors such as Oracle Corporation, Microsoft Corporation, IBM, and open source projects including PostgreSQL and MySQL. Revisions have aimed to address extensibility and portability concerns raised by database researchers from University of California, Berkeley, Massachusetts Institute of Technology, and industrial labs at IBM Research and Google Research. Ongoing work in committees sponsored by ISO and IEC continues to balance backward compatibility with modern requirements driven by organizations like Netflix, Facebook, and Amazon.

Category:ISO standards