#pragma once #include #include namespace DB { /// Sort one block by `description`. If limit != 0, then the partial sort of the first `limit` rows is produced. void sortBlock(Block & block, const SortDescription & description, UInt64 limit = 0); /** Used only in StorageMergeTree to sort the data with INSERT. * Sorting is stable. This is important for keeping the order of rows in the CollapsingMergeTree engine * - because based on the order of rows it is determined whether to delete or leave groups of rows when collapsing. * Collations are not supported. Partial sorting is not supported. */ void stableSortBlock(Block & block, const SortDescription & description); /** Same as stableSortBlock, but do not sort the block, but only calculate the permutation of the values, * so that you can rearrange the column values yourself. */ void stableGetPermutation(const Block & block, const SortDescription & description, IColumn::Permutation & out_permutation); /** Quickly check whether the block is already sorted. If the block is not sorted - returns false as fast as possible. * Collations are not supported. */ bool isAlreadySorted(const Block & block, const SortDescription & description); }