/**
 * @copyright Sister Software
 * @license AGPL-3.0
 * @author Teffen Ellis, et al.
 * @file Promise-based parquet reads. The iterator-based reads live in `./streams`.
 *
 *   {@linkcode readParquetRows} throws when the file is missing. {@linkcode tryReadParquetRows} returns `null`.
 *   Both throw for an unreadable file, so a caller cannot mistake a read failure for an empty file.
 */
import type { PathBuilderLike } from "path-ts";
import { type ParquetRowStreamOptions } from "#parquet/streams";
/**
 * Reads every row of a parquet file into memory.
 *
 * Use {@linkcode openParquetRowStream} for a file too large to hold in memory.
 *
 * @throws When the file is missing or `columns` includes a column the file lacks.
 */
export declare function readParquetRows<T>(path: PathBuilderLike, options?: ParquetRowStreamOptions): Promise<T[]>;
/**
 * Reads every row of a parquet file, or returns `null` when the file is missing.
 *
 * @throws When the file cannot be parsed or `columns` includes a column the file lacks.
 */
export declare function tryReadParquetRows<T>(path: PathBuilderLike, options?: ParquetRowStreamOptions): Promise<T[] | null>;
/**
 * Counts the rows of a parquet file from its metadata, so the cost stays flat as the row count grows.
 *
 * The function opens its own DuckDB connection.
 *
 * @throws When the file is missing.
 */
export declare function countParquetRows(path: PathBuilderLike): Promise<number>;
/**
 * Returns a parquet file's column names in file order.
 *
 * The query uses `DESCRIBE`, which lists logical columns.
 * `parquet_schema` lists physical leaves instead, where a list column such as
 * `tokens` appears only as its `element` child.
 *
 * @throws When the file is missing.
 */
export declare function parquetColumnNames(path: PathBuilderLike): Promise<string[]>;
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