Overview
ISO/IEC 19075-9:2022 - Information technology - Guidance for the use of database language SQL - Part 9: Online analytic processing (OLAP) capabilities (Guide/OLAP) provides guidance on the syntax and semantics for adding OLAP capabilities to SQL (as defined in ISO/IEC 9075-2). The standard documents how SQL can express analytical operations such as ranking, distribution, windowing, moving aggregates and enhanced numeric/aggregate functions. It includes worked examples, tables and explanatory text to support implementation and usage.
Key topics
The standard discusses the following OLAP features and related technical requirements:
- Window definitions and windows clause: partitioning, ordering, physical and logical window frames (RANGE, GROUPS), frame exclusions and multiple/implicit vs explicit windows.
- Window frame semantics: UNBOUNDED / PRECEDING / FOLLOWING, FRAME_ROW behavior and exclusions (EXCLUDE).
- Window functions: RANK, DENSE_RANK, ROW_NUMBER, distribution functions (PERCENT_RANK, CUME_DIST), and window aggregate functions.
- Distribution and percentile support: NTILE function and its behavior in partitioned/non‑partitioned queries.
- Lead/lag and accessors: LEAD, LAG, with the null treatment option and row offsets.
- First/last and nth element functions: FIRST_VALUE, LAST_VALUE, NTH_VALUE.
- Nested window functions: rules for nesting, row markers, offsets and interactions with FRAME_ROW.
- Enhanced numeric and aggregate functions: unary/binary statistical aggregates, hypothetical rank/distribution aggregates and inverse distribution functions.
- Null handling rules and explicit examples showing expected results.
Applications
ISO/IEC 19075-9:2022 is targeted at practical OLAP use cases in SQL:
- Building analytical queries for BI dashboards (rankings, percentiles, cohorts).
- Implementing moving averages, running totals and sliding-window calculations in data warehouses.
- Producing reproducible percentile/quantile calculations via NTILE and inverse distribution functions.
- Handling lead/lag comparisons and time-series offsets robustly (including null treatment).
- Designing and validating SQL engine implementations and ensuring consistent semantics for windowing and nested window functions.
Who uses this standard
- Database vendors and SQL engine implementers (conformance and feature design).
- Database administrators, data engineers and BI developers (writing portable analytical SQL).
- Technical architects and consultants designing data warehouse/analytics platforms.
- Standards bodies and compliance teams referencing ISO/IEC guidance for SQL OLAP features.
Related standards
ISO/IEC 19075-9:2022 is a practical resource for anyone implementing or using advanced SQL OLAP features - window functions, NTILE, LEAD/LAG, nested windows, GROUPS and enhanced aggregate functions - to produce reliable, portable analytical SQL.