julienledem commented on code in PR #254: URL: https://github.com/apache/parquet-format/pull/254#discussion_r1623070786
########## README.md: ########## @@ -285,6 +285,61 @@ There are many places in the format for compatible extensions: - Encodings: Encodings are specified by enum and more can be added in the future. - Page types: Additional page types can be added and safely skipped. +### Thrift extensions +Thrift is used for metadata. The Thrift spec mandates that unknown fields are +skipped. To facilitate extensions Parquet reserves field-id `32767` of *every* +struct as an ignorable extension point. More specifically Parquet guarantees +that field-id `32767` will *never* be seen in the official Thrift IDL. The type +of this field is always `binary`. Review Comment: I assume we constraint this to binary so that skipping it takes the least amount of time. It might be worth mentioning it here. -- 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]
