Overview
ISO/IEC 9075-9:2016/Cor 2:2022 is Technical Corrigendum 2 to Part 9 of the SQL standard (SQL/MED), published June 2022 by ISO/IEC JTC 1/SC 32. SQL/MED (Management of External Data) defines language elements and behaviour for accessing, mapping and controlling external data sources from an SQL database (for example, foreign servers, foreign-data wrappers and datalink values). This corrigendum issues precise corrections and clarifications to the original 2016 text to ensure interoperable implementation and unambiguous semantics.
Key topics and technical changes
The corrigendum clarifies and corrects rule text in several subclauses of ISO/IEC 9075-9:2016. Notable technical items include:
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Datalink value function (6.6)
- Makes explicit behavior when a DLOC is null: if DLVALUE is specified and DLOC is the null value, then the datalink value function (DVC) result is the null value. It also clarifies that no further subrules of that general rule are applied in that case.
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Access control and privileges (13.1)
- Replaces permissive wording and tightens privilege requirements. If an ON clause specifies a
or a, the access control (AC) clause shall specify the USAGE privilege. This removes ambiguity about required privileges for external data access.
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SQL/MED common specifications (21.5)
- Corrects terminology for implicit EXECUTE USING and OPEN USING clauses to reference the proper FDW execution naming (ALLOCATED FDW-EXECUTION). This is a naming/consistency correction to align the subclause with the rest of SQL/Foundation and SQL/MED rules.
Practical applications
This corrigendum is important for:
- DBMS implementers who must update SQL/MED implementations to match clarified behaviors for datalink functions, privilege enforcement, and FDW execution semantics.
- Database architects and administrators who define foreign servers, data wrappers and privilege grants - the corrigendum helps ensure consistent, secure configuration (notably requiring USAGE when applicable).
- Security auditors and compliance teams reviewing privilege policies and external-data access controls.
- Application developers relying on predictable SQL/MED behavior when integrating external data sources.
Related standards
- ISO/IEC 9075 family (SQL) - SQL/Foundation and other parts of the standard are referenced for consistent semantics across SQL language features.
- SQL/MED (ISO/IEC 9075-9:2016) - this corrigendum amends that part.
Keywords: ISO/IEC 9075-9, SQL/MED, external data, foreign data wrapper, foreign server, datalink, access control, USAGE privilege, SQL standard, corrigendum.