Module selection 

Logic for selecting which rows to read: RowSelection and RowSelector

This module holds RowSelection and its public API, which dispatches to one of the two backings depending on how the selection is stored:

• selector: the run length backing, RowSelector and its primitives
• boolean: the bitmap backing, MaskSelection and its primitives

The remaining modules hold the operations that are common to both:

• algebra: and_then, intersection and union
• ranges: mapping a RowSelection onto page and batch ranges
• cursor: iterating a RowSelection while reading

Re-exports

pub use boolean::MaskRunIter;

pub use cursor::RowSelectionCursor;

pub use cursor::RowSelectionPolicy;

pub use selector::RowSelector;

Modules

algebra 🔒

Set algebra backing RowSelection::and_then, RowSelection::intersection and RowSelection::union

boolean 🔒

The bitmap backed representation of a RowSelection and the primitives operating on it: conversion to and from the run length (RowSelector) form, and the transforms backing split_off, trim, offset and limit.

cursor 🔒

Execution time iteration over a RowSelection.

ranges 🔒

Mapping the RowSelector runs of a selection onto ranges: the byte ranges of the data pages that must be fetched (RowSelection::scan_ranges) and the expansion of a selection to batch boundaries.

selector 🔒

The run length backed representation of a RowSelection: RowSelector and the primitives operating on a sequence of them.

Structs

RowSelection

RowSelection represents selecting a subset of rows when scanning a parquet file.

Enums

RowSelectionInner 🔒

Internal storage for RowSelection.

Functions

append_normalized_selector 🔒

Appends a selector while maintaining the normalized selector invariants.

auto_min_mask_runs 🔒

Returns the minimum normalized run count for which the Auto selection policy would prefer a mask to RLE.

filters_to_boolean_buffer 🔒

selectors_below_run_limit 🔒

Builds normalized selectors while their run count remains below min_mask_runs. Returning None drops the partial selector allocation before the caller constructs a mask.