rdblue commented on code in PR #585: URL: https://github.com/apache/parquet-format/pull/585#discussion_r3573978844
########## LogicalTypes.md: ########## @@ -635,7 +635,173 @@ The type has two type parameters: The sort order used for `GEOGRAPHY` is undefined. When writing data, no min/max statistics should be saved for this type and if such non-compliant statistics -are found during reading, they must be ignored. +are found during reading, they must be ignored. + +### FILE + +`FILE` annotates a group that represents a reference to a range of bytes, which may +be stored inline in the value, elsewhere within the current file, or in an external file. It +is intended for use cases such as storing file inventories, manifests, and unstructured +data references (e.g., images or audio files stored in object storage). + +The annotated group may contain the following fields, identified by name case sensitively, +not by field order. Field IDs, if they exist, may also be used for projection. Every field +is optional both in the schema and in the data: a writer may omit any field from the group +definition, and any field that is present has a field repetition type of `OPTIONAL`. +A group need only define the fields it uses (for example, an inline-only group may define +just `inline`, and an external reference may define just `path`). + +| Field | Type | +|----------------|------------| +| `path` | STRING | +| `offset` | INT64 | +| `size` | INT64 | +| `content_type` | STRING | +| `checksum` | STRING | +| `inline` | BYTE_ARRAY | + +A value resolves to bytes determined by `inline` / `path` / `offset` / `size`; +`content_type` and `checksum` are metadata describing whatever is resolved. + +#### Fields + +For the descriptions below, a field is *set* when it is present in the `FILE` group +and its value is non-null (and, for string fields, non-empty). A field is *not set* Review Comment: Nit: we should be clear that implementations are not expected to treat empty strings as null. -- 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]
