RussellSpitzer commented on code in PR #12841: URL: https://github.com/apache/iceberg/pull/12841#discussion_r2059275200
########## format/spec.md: ########## @@ -266,7 +266,11 @@ The `initial-default` is set only when a field is added to an existing schema. T The `initial-default` and `write-default` produce SQL default value behavior, without rewriting data files. SQL default value behavior when a field is added handles all existing rows as though the rows were written with the new field's default value. Default value changes may only affect future records and all known fields are written into data files. Omitting a known field when writing a data file is never allowed. The write default for a field must be written if a field is not supplied to a write. If the write default for a required field is not set, the writer must fail. -All columns of `unknown`, `geometry`, and `geography` types must default to null. Non-null values for `initial-default` or `write-default` are invalid. +All columns of `unknown`, `variant`, `geometry`, and `geography` types must default to null. Non-null values for `initial-default` or `write-default` are invalid. + +Default values for the fields of a struct are tracked as `initial-default` and `write-default` at the field level. Default values for fields that are nested structs must not contain default values for the struct's fields (sub-fields). Sub-field defaults are tracked in sub-field's metadata. As a result, the default stored for a nested struct may be either null or a non-null struct with no field values. The actual default value is produced by setting each field default in a new struct. Review Comment: I thought 'empty' meant a struct with no field values? When I read "with no field values" i'm a little lost because what does that mean that isn't empty? "Effective default value is produced" sounds good to me, "actual" seems ambiguous. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: issues-unsubscr...@iceberg.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@iceberg.apache.org For additional commands, e-mail: issues-h...@iceberg.apache.org
