Overview
ISO/IEC 9075-11:2023 - Part 11 of the SQL standard - defines the standardized Information Schema and Definition Schema for SQL implementations. Published as the fifth edition in June 2023, this part of ISO/IEC 9075 specifies the metadata structures, lexical conventions and conformance rules that enable consistent schema introspection, metadata exchange and definition of database objects across compliant systems.
Key topics and technical scope
This standard focuses on the formal representation of database metadata and includes:
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Information Schema (INFORMATION_SCHEMA)
- A comprehensive set of standardized read-only views and domains for runtime metadata (examples from the table of contents: COLUMNS, TABLES, VIEWS, ROUTINES, SCHEMATA, SEQUENCES, TABLE_CONSTRAINTS, COLUMN_PRIVILEGES, etc.).
- Domain definitions such as SQL_IDENTIFIER, TIME_STAMP, CHARACTER_DATA, CARDINAL_NUMBER, and YES_OR_NO to standardize metadata value types.
- Views covering features, privileges, character sets, collations and usage relationships (e.g., CHARACTER_SETS, COLLATIONS, ROLE_TABLE_GRANTS).
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Definition Schema (DEFINITION_SCHEMA)
- Basetables and assertions that represent the definitional metadata of a database (for example: TABLESbasetable, COLUMNSbasetable, ROUTINESbasetable).
- Assertions and integrity rules for key degrees and uniqueness to support consistent definition semantics.
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Lexical elements and notations
- Tokens, separators and conventions used in schema descriptions.
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Conformance and implementation guidance
- Conformance claims, required and optional features, and annexes detailing implementation-defined and implementation-dependent elements, deprecated features and incompatibilities.
Practical applications and users
ISO/IEC 9075-11:2023 is used wherever standardized access to database metadata and schema definitions is required:
- DBMS vendors - implement the INFORMATION_SCHEMA and DEFINITION_SCHEMA to achieve SQL compliance and interoperability.
- Application developers and ORMs - use standardized metadata for schema discovery, dynamic SQL generation and migrations.
- DBAs and architects - automate inventory, governance, auditing and compatibility checks across heterogeneous database systems.
- Tooling vendors - build cross-platform management, migration, reverse-engineering and documentation tools.
- Test labs and compliance assessors - verify SQL/Schemata conformance and portability.
Related standards
- ISO/IEC 9075 (the overall SQL standard family) - Part 11 is one component that ensures consistent metadata semantics across the broader SQL standard.
Keywords: ISO/IEC 9075-11:2023, SQL Information Schema, DEFINITION_SCHEMA, INFORMATION_SCHEMA, database metadata, schema introspection, SQL standard, conformance, database portability.