ISO IEC 19075-5-2021 PDF

Full title and description

ISO/IEC 19075-5:2021 — Information technology — Guidance for the use of database language SQL — Part 5: Row pattern recognition. This part provides guidance on the syntax and semantics used to recognise patterns of rows in a table (the SQL Row Pattern Recognition facility, commonly called SQL/RPR) and explains how the feature is placed in either the FROM clause or the WINDOW clause of SQL statements.

Abstract

This document discusses the syntax and semantics for recognising row patterns as defined by SQL/RPR. It describes the two main feature placements — R010 (Row pattern recognition: FROM clause) and R020 (Row pattern recognition: WINDOW clause) — explains their common syntax and semantics, and illustrates differences in behaviour, handling of empty matches, measures and window interactions with worked examples and mappings to SQL/9075 constructs.

General information

• Status: Published.
• Publication date: August 2021 (2021-08).
• Publisher: International Organization for Standardization (ISO) / International Electrotechnical Commission (IEC), JTC 1/SC 32 (Data management and interchange).
• ICS / categories: 35.060 (Information technology — Databases).
• Edition / version: Edition 1 (first edition, 2021).
• Number of pages: 74 pages.

Scope

Defines guidance for the use of SQL Row Pattern Recognition (SQL/RPR): syntax summaries, semantic rules, examples, and interactions with window functions and other SQL features. It is intended to be used together with the relevant parts of the ISO/IEC 9075 (SQL) series and provides implementer-oriented guidance rather than normative changes to the core SQL language. This edition replaces the earlier technical report on the same subject (ISO/IEC TR 19075-5:2016).

Key topics and requirements

• Explanation of row pattern recognition concepts and terminology (SQL/RPR).
• Detailed syntax summaries for pattern declarations when used in FROM and WINDOW clauses.
• Semantic rules for matching behaviour, including treatment of empty matches and nested/multi-match scenarios.
• Interaction rules between pattern recognition and window functions, measures, and partitioning.
• Worked examples and illustrative query results to clarify expected implementer behaviour.
• Guidance for mapping SQL/RPR features to other SQL/9075 parts and implementer notes for DBMS vendors.

Typical use and users

Primary users are DBMS implementers, SQL language designers, and query-engine developers who need concrete guidance to implement row pattern recognition features. Secondary users include advanced SQL developers, data engineers, and technical authors who need to understand pattern-matching behaviour for analytics, event-sequence detection, or complex time-series queries.

Related standards

This part is a member of the ISO/IEC 19075 series (guidance for the use of the SQL language) and is intended for use with the ISO/IEC 9075 (SQL) series (notably parts covering core SQL, window functions and related features). It cancels and replaces ISO/IEC TR 19075-5:2016; related parts in the 19075 series include other guidance parts (for example parts addressing arrays, OLAP and JSON guidance in companion documents published in the same timeframe).

Keywords

SQL, SQL/RPR, row pattern recognition, pattern matching, WINDOW clause, FROM clause, SQL guidance, ISO/IEC 9075, DBMS implementation, window functions.

FAQ

Q: What is this standard?

A: ISO/IEC 19075-5:2021 is an international guidance document that explains how to use the SQL Row Pattern Recognition facility (SQL/RPR), providing syntax and semantic guidance and examples for implementers and users of advanced SQL pattern-matching features.

Q: What does it cover?

A: It covers the syntax summaries and semantic rules for row pattern recognition, the two feature placements (FROM and WINDOW clause variants), handling of empty matches, interactions with window functions and measures, and worked examples to illustrate expected behaviour.

Q: Who typically uses it?

A: DBMS implementers, SQL standard editors, query-engine developers, advanced SQL developers and data engineers who implement or use SQL pattern-recognition features for analytics and event-sequence queries.

Q: Is it current or superseded?

A: This document is the published (current) first edition from August 2021 and it cancels/supersedes the earlier Technical Report ISO/IEC TR 19075-5:2016.

Q: Is it part of a series?

A: Yes — it is Part 5 of the ISO/IEC 19075 series (Guidance for the use of the database language SQL) and is intended to be used alongside the ISO/IEC 9075 (SQL) standard parts.

Q: What are the key keywords?

A: SQL, row pattern recognition, SQL/RPR, pattern matching, WINDOW, FROM, window functions, ISO/IEC 9075.