lance-core 0.38.2

Lance Columnar Format -- Core Library
Documentation 
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// SPDX-License-Identifier: Apache-2.0
// SPDX-FileCopyrightText: Copyright The Lance Authors

use arrow_schema::{DataType, Field as ArrowField};
use std::sync::LazyLock;

pub mod cache;
pub mod container;
pub mod datatypes;
pub mod error;
pub mod traits;
pub mod utils;

pub use error::{ArrowResult, Error, Result};

/// Column name for the meta row ID.
pub const ROW_ID: &str = "_rowid";
/// Column name for the meta row address.
pub const ROW_ADDR: &str = "_rowaddr";
/// Column name for the meta row offset.
pub const ROW_OFFSET: &str = "_rowoffset";

/// Row ID field. This is nullable because its validity bitmap is sometimes used
/// as a selection vector.
pub static ROW_ID_FIELD: LazyLock<ArrowField> =
    LazyLock::new(|| ArrowField::new(ROW_ID, DataType::UInt64, true));
/// Row address field. This is nullable because its validity bitmap is sometimes used
/// as a selection vector.
pub static ROW_ADDR_FIELD: LazyLock<ArrowField> =
    LazyLock::new(|| ArrowField::new(ROW_ADDR, DataType::UInt64, true));
/// Row offset field. This is nullable merely for compatibility with the other
/// fields.
pub static ROW_OFFSET_FIELD: LazyLock<ArrowField> =
    LazyLock::new(|| ArrowField::new(ROW_OFFSET, DataType::UInt64, true));