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alamb merged 1 commit into from
Aug 25, 2026
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docs: Revise Parquet metadata module documentation #10796

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43 changes: 3 additions & 40 deletions parquet/src/file/metadata/mod.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -32,10 +32,12 @@
//! within a Row Group including encoding and compression information,
//! number of values, statistics, etc.
//!
//! * [`PageIndex`]: Metadata and statistics used to reduce page-level I/O.
//!
//! # APIs for working with Parquet Metadata
//!
//! The Parquet readers and writers in this crate handle reading and writing
//! metadata into parquet files. To work with metadata directly,
//! metadata into Parquet files. To work with metadata directly,
//! the following APIs are available:
//!
//! * [`ParquetMetaDataReader`] for reading metadata from an I/O source (sync and async)
Expand All @@ -47,45 +49,6 @@
//! Please see [`external_metadata.rs`]
//!
//! [`external_metadata.rs`]: https://github.com/apache/arrow-rs/tree/master/parquet/examples/external_metadata.rs
//!
//! # Metadata Encodings and Structures
//!
//! There are three different encodings of Parquet Metadata in this crate:
//!
//! 1. `bytes`:encoded with the Thrift `TCompactProtocol` as defined in
//! [parquet.thrift]
//!
//! 2. [`format`]: Rust structures automatically generated by the thrift compiler
//! from [parquet.thrift]. These structures are low level and mirror
//! the thrift definitions.
//!
//! 3. [`file::metadata`] (this module): Easier to use Rust structures
//! with a more idiomatic API. Note that, confusingly, some but not all
//! of these structures have the same name as the [`format`] structures.
//!
//! [`file::metadata`]: crate::file::metadata
//! [parquet.thrift]: https://github.com/apache/parquet-format/blob/master/src/main/thrift/parquet.thrift
//!
//! Graphically, this is how the different structures relate to each other:
//!
//! ```text
//! ┌ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ┌ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─
//! ┌──────────────┐ │ ┌───────────────────────┐ │
//! │ │ ColumnIndex │ ││ ParquetMetaData │
//! └──────────────┘ │ └───────────────────────┘ │
//! ┌──────────────┐ │ ┌────────────────┐ │┌───────────────────────┐
//! │ ..0x24.. │ ◀────▶ │ OffsetIndex │ │ ◀────▶ │ ParquetMetaData │ │
//! └──────────────┘ │ └────────────────┘ │└───────────────────────┘
//! ... │ ... │
//! │ ┌──────────────────┐ │ ┌──────────────────┐
//! bytes │ FileMetaData* │ │ │ FileMetaData* │ │
//! (thrift encoded) │ └──────────────────┘ │ └──────────────────┘
//! ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ┘ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ┘
//!
//! format::meta structures file::metadata structures
//!
//! * Same name, different struct
//! ```
mod footer_tail;
mod memory;
mod options;
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