Feature Request : Support Iceberg Identifier Fields

[lozbrown]

The Iceberg spec mentions

Identifier Field IDs
A schema can optionally track the set of primitive fields that identify rows in a table, using the property identifier-field-ids (see JSON encoding in Appendix C).

Two rows are the "same"---that is, the rows represent the same entity---if the identifier fields are equal. However, uniqueness of rows by this identifier is not guaranteed or required by Iceberg and it is the responsibility of processing engines or data providers to enforce.

Identifier fields may be nested in structs but cannot be nested within maps or lists. Float, double, and optional fields cannot be used as identifier fields and a nested field cannot be used as an identifier field if it is nested in an optional struct, to avoid null values in identifiers.

Support defining Identifier Field IDs when creating tables and showing that these are identifier fields when displaying with "show create table"

As above no expectation of enforcing these is required in Trino but the creation, storage and access to this metadata would be helpful to those creating automated processes to merge tables.