ClickHouse/dbms/Storages/MergeTree/MergeTreeDataSelectExecutor.h
Ivan 97f2a2213e
Move all folders inside /dbms one level up (#9974)
* Move some code outside dbms/src folder
* Fix paths
2020-04-02 02:51:21 +03:00

108 lines
3.4 KiB
C++

#pragma once
#include <Core/QueryProcessingStage.h>
#include <Storages/SelectQueryInfo.h>
#include <Storages/MergeTree/MergeTreeData.h>
#include <Storages/MergeTree/RangesInDataPart.h>
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<String, Int64>;
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;
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) const;
Pipes spreadMarkRangesAmongStreamsFinal(
RangesInDataParts && parts,
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;
/// 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;
};
}