Thank you Russel. I updated the language to focus on reader semantics and saying that a reader can choose to read either.
On Mon, Aug 24, 2026 at 4:37 PM Russell Spitzer <[email protected]> wrote: > +1, Although I'm not sure we should add language about the bytes in the > location and inline *must* being the same. Since i'm not sure it's > something we could actually control from within the parquet universe. If a > writer knows the two are identical at the time of writing the row is that > enough? I think it's fine to outline the fallback behavior and just say, > "When a locator is present, it is implied that a reader can either use the > locator or inline bytes interchangeably." > > On Mon, Aug 24, 2026 at 9:03 AM Alkis Evlogimenos via dev < > [email protected]> wrote: > >> Hi folks, >> >> I would like to start a vote on adopting the format change in PR 603 [1]: >> remove self-references from the FILE logical type. This came out of the >> discussion on inheriting the inline codec [2]. >> >> FILE as merged lets a value set offset and size with no uri, which >> addresses a byte range inside the containing file. This byte range is >> effectively owned by the Parquet writer. Specifying that range properly >> means giving it a compression block, an encryption module, an AAD >> identity, >> and its own size accounting. That is a second page mechanism reachable >> only >> through FILE. The use case is mid sized values and it is better served by >> non-contiguous pages, which we will propose separately. Removing >> self-references keeps FILE to the forms it specifies cleanly, while the >> format has not shipped in a release. >> >> The changes: >> >> 1. Remove self-references. A value that sets offset and size with no uri >> is >> invalid. offset may only be set together with uri. >> 2. Resolve uri uniformly as an external reference, including when it names >> the file that contains it. Parquet applies no compression or encryption of >> its own to those bytes. The parquet writer does NOT own these bytes. An >> earlier draft forbade referencing the current file, but neither a writer >> nor a reader can check that, so the encoding is uniform instead. >> 3. Drop the prohibition on modular encryption. It existed only because >> self-referenced ranges were not encryption modules. The fields of a FILE >> group are ordinary columns and are encoded, compressed, and encrypted like >> any other column, inline included. >> 4. Allow inline together with the locator fields. Both must denote the >> same >> bytes, so a reader may resolve from either and get the same result, and >> inline is the cheaper path because it needs no external access. If the two >> disagree the value is invalid, and a reader is not required to detect it. >> This combination was underspecified before. >> >> The spec changes are in https://github.com/apache/parquet-format/pull/603 >> and touch LogicalTypes.md and a comment in parquet.thrift. Encryption.md >> is >> unchanged from master and no Thrift structures change. Inline and external >> references behave as before for existing readers and writers. >> >> Please vote in the next 72 hours. >> >> [ ] +1 Approve the proposed format change >> [ ] +0 No opinion >> [ ] -1 Do not approve (please provide specific reasons) >> >> Cheers, >> >> [1] https://github.com/apache/parquet-format/pull/603 >> [2] https://lists.apache.org/thread/zrzc7t9fccg92rx3h4fw3ndw3bdo5xr7 >> >
