Clarification on GetObjects FOREIGN KEY

[CurtHagenlocher]

What would you like help with?

Is the intent of the FOREIGN KEY constraints returned by AdbcConnectionGetObjects that they include relational constraints in both directions? That is, for a CUSTOMER table defined as in TPC-H, should it return both "ORDERS"."CUSTKEY" (which references "CUSTOMER"."CUSTKEY") and "NATION"."NATIONKEY" (which is referenced by "CUSTOMER"."NATIONKEY")?

If so, the documentation could probably be improved by indicating this explicitly.

If not, if it only returns references in one direction then this is a feature gap with ODBC and JDBC.

[lidavidm]

I think from reading the GetObjects schema definition, only JDBC's getImportedKeys is supported, effectively. We would need to add something to cover getExportedKeys, probably by extending the constraint_type (adding EXPORTED KEY?)

[lidavidm]

This got raised again as #3988, I'll merge that into this since this was first.

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CONSTRAINT_SCHEMA exposes which columns on a table reference other columns, but not the reverse.

I think the main question is whether we try to fit this in the existing GetObjects schema or expose it under a new function.

• JDBC: getExportedKeys
• ODBC: SQLForeignKeys
• BigQuery: Feature Request: Comprehensive Metadata Discovery for Data Development Tools adbc-drivers/bigquery#118 (point 8)
• PostgreSQL: Feature Request: [postgresql] Comprehensive Metadata Discovery for Data Development Tools #3971 (point 13)