#pragma once #include #include #include #include namespace DB { class KeyCondition; /** Executes SELECT queries on data from the merge tree. */ class MergeTreeDataSelectExecutor { public: explicit MergeTreeDataSelectExecutor(const MergeTreeData & data_); /** When reading, selects a set of parts that covers the desired range of the index. * max_blocks_number_to_read - if not nullptr, do not read all the parts whose right border is greater than max_block in partition. */ using PartitionIdToMaxBlock = std::unordered_map; Pipes read( const Names & column_names, const SelectQueryInfo & query_info, const Context & context, UInt64 max_block_size, unsigned num_streams, const PartitionIdToMaxBlock * max_block_numbers_to_read = nullptr) const; Pipes readFromParts( MergeTreeData::DataPartsVector parts, const Names & column_names, const SelectQueryInfo & query_info, const Context & context, UInt64 max_block_size, unsigned num_streams, const PartitionIdToMaxBlock * max_block_numbers_to_read = nullptr) const; private: const MergeTreeData & data; Logger * log; Pipes spreadMarkRangesAmongStreams( RangesInDataParts && parts, size_t num_streams, const Names & column_names, UInt64 max_block_size, bool use_uncompressed_cache, const SelectQueryInfo & query_info, const Names & virt_columns, const Settings & settings, const MergeTreeReaderSettings & reader_settings) const; /// out_projection - save projection only with columns, requested to read Pipes spreadMarkRangesAmongStreamsWithOrder( RangesInDataParts && parts, size_t num_streams, const Names & column_names, UInt64 max_block_size, bool use_uncompressed_cache, const SelectQueryInfo & query_info, const ExpressionActionsPtr & sorting_key_prefix_expr, const Names & virt_columns, const Settings & settings, const MergeTreeReaderSettings & reader_settings, ExpressionActionsPtr & out_projection) const; Pipes spreadMarkRangesAmongStreamsFinal( RangesInDataParts && parts, size_t num_streams, const Names & column_names, UInt64 max_block_size, bool use_uncompressed_cache, const SelectQueryInfo & query_info, const Names & virt_columns, const Settings & settings, const MergeTreeReaderSettings & reader_settings, ExpressionActionsPtr & out_projection) const; /// Get the approximate value (bottom estimate - only by full marks) of the number of rows falling under the index. size_t getApproximateTotalRowsToRead( const MergeTreeData::DataPartsVector & parts, const KeyCondition & key_condition, const Settings & settings) const; /// Create the expression "Sign == 1". void createPositiveSignCondition( ExpressionActionsPtr & out_expression, String & out_column, const Context & context) const; MarkRanges markRangesFromPKRange( const MergeTreeData::DataPartPtr & part, const KeyCondition & key_condition, const Settings & settings) const; MarkRanges filterMarksUsingIndex( MergeTreeIndexPtr index, MergeTreeIndexConditionPtr condition, MergeTreeData::DataPartPtr part, const MarkRanges & ranges, const Settings & settings) const; }; }