gszadovszky commented on code in PR #469: URL: https://github.com/apache/parquet-format/pull/469#discussion_r1827552044
########## LogicalTypes.md: ########## @@ -709,13 +709,18 @@ to values. `MAP` must annotate a 3-level structure: * The outer-most level must be a group annotated with `MAP` that contains a single field named `key_value`. The repetition of this level must be either - `optional` or `required` and determines whether the list is nullable. + `optional` or `required` and determines whether the map is nullable. * The middle level, named `key_value`, must be a repeated group with a `key` - field for map keys and, optionally, a `value` field for map values. + field for map keys and, optionally, a `value` field for map values. It must + not contain any other values. * The `key` field encodes the map's key type. This field must have - repetition `required` and must always be present. + repetition `required` and must always be present. I must be placed at the 0th + position of the `key_value` group. It is suggested to use a primitive as the + type. * The `value` field encodes the map's value type and repetition. This field can - be `required`, `optional`, or omitted. + be `required`, `optional`, or omitted. It must be placed at the 1st position + of the `key_value` group if present. In case of not present, the map can be + either represented with all null values or as a set of keys. Review Comment: Yeah, I've never seen an actual use-case implemented for this one either. I am open to require having a value but since it is out there for a while now, I am not sure if we can do it. Maybe a suggestion to always specify a value and let it be an optional with all nulls if one would not use it? -- 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: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
