ClickHouse/src/Storages/MergeTree/IMergeTreeDataPart.h
2022-01-21 21:55:42 +03:00

518 lines
21 KiB
C++

#pragma once
#include <Core/Block.h>
#include <base/types.h>
#include <Core/NamesAndTypes.h>
#include <Storages/IStorage.h>
#include <Storages/MergeTree/MergeTreeIndexGranularity.h>
#include <Storages/MergeTree/MergeTreeIndexGranularityInfo.h>
#include <Storages/MergeTree/MergeTreeIndices.h>
#include <Storages/MergeTree/MergeTreePartInfo.h>
#include <Storages/MergeTree/MergeTreePartition.h>
#include <Storages/MergeTree/MergeTreeDataPartChecksum.h>
#include <Storages/MergeTree/MergeTreeDataPartTTLInfo.h>
#include <Storages/MergeTree/MergeTreeIOSettings.h>
#include <Storages/MergeTree/KeyCondition.h>
#include <DataTypes/Serializations/SerializationInfo.h>
#include <shared_mutex>
namespace zkutil
{
class ZooKeeper;
using ZooKeeperPtr = std::shared_ptr<ZooKeeper>;
}
namespace DB
{
struct ColumnSize;
class MergeTreeData;
struct FutureMergedMutatedPart;
class IReservation;
using ReservationPtr = std::unique_ptr<IReservation>;
class IVolume;
using VolumePtr = std::shared_ptr<IVolume>;
class IMergeTreeReader;
class IMergeTreeDataPartWriter;
class MarkCache;
class UncompressedCache;
/// Description of the data part.
class IMergeTreeDataPart : public std::enable_shared_from_this<IMergeTreeDataPart>
{
public:
static constexpr auto DATA_FILE_EXTENSION = ".bin";
using Checksums = MergeTreeDataPartChecksums;
using Checksum = MergeTreeDataPartChecksums::Checksum;
using ValueSizeMap = std::map<std::string, double>;
using MergeTreeReaderPtr = std::unique_ptr<IMergeTreeReader>;
using MergeTreeWriterPtr = std::unique_ptr<IMergeTreeDataPartWriter>;
using ColumnSizeByName = std::unordered_map<std::string, ColumnSize>;
using NameToNumber = std::unordered_map<std::string, size_t>;
using IndexSizeByName = std::unordered_map<std::string, ColumnSize>;
using Type = MergeTreeDataPartType;
IMergeTreeDataPart(
const MergeTreeData & storage_,
const String & name_,
const MergeTreePartInfo & info_,
const VolumePtr & volume,
const std::optional<String> & relative_path,
Type part_type_,
const IMergeTreeDataPart * parent_part_);
IMergeTreeDataPart(
const MergeTreeData & storage_,
const String & name_,
const VolumePtr & volume,
const std::optional<String> & relative_path,
Type part_type_,
const IMergeTreeDataPart * parent_part_);
virtual MergeTreeReaderPtr getReader(
const NamesAndTypesList & columns_,
const StorageMetadataPtr & metadata_snapshot,
const MarkRanges & mark_ranges,
UncompressedCache * uncompressed_cache,
MarkCache * mark_cache,
const MergeTreeReaderSettings & reader_settings_,
const ValueSizeMap & avg_value_size_hints_ = ValueSizeMap{},
const ReadBufferFromFileBase::ProfileCallback & profile_callback_ = ReadBufferFromFileBase::ProfileCallback{}) const = 0;
virtual MergeTreeWriterPtr getWriter(
const NamesAndTypesList & columns_list,
const StorageMetadataPtr & metadata_snapshot,
const std::vector<MergeTreeIndexPtr> & indices_to_recalc,
const CompressionCodecPtr & default_codec_,
const MergeTreeWriterSettings & writer_settings,
const MergeTreeIndexGranularity & computed_index_granularity = {}) const = 0;
virtual bool isStoredOnDisk() const = 0;
virtual bool isStoredOnRemoteDisk() const = 0;
virtual bool supportsVerticalMerge() const { return false; }
/// NOTE: Returns zeros if column files are not found in checksums.
/// Otherwise return information about column size on disk.
ColumnSize getColumnSize(const String & column_name) const;
/// NOTE: Returns zeros if secondary indexes are not found in checksums.
/// Otherwise return information about secondary index size on disk.
IndexSize getSecondaryIndexSize(const String & secondary_index_name) const;
/// Return information about column size on disk for all columns in part
ColumnSize getTotalColumnsSize() const { return total_columns_size; }
/// Return information about secondary indexes size on disk for all indexes in part
IndexSize getTotalSeconaryIndicesSize() const { return total_secondary_indices_size; }
virtual String getFileNameForColumn(const NameAndTypePair & column) const = 0;
virtual ~IMergeTreeDataPart();
using ColumnToSize = std::map<std::string, UInt64>;
/// Populates columns_to_size map (compressed size).
void accumulateColumnSizes(ColumnToSize & /* column_to_size */) const;
Type getType() const { return part_type; }
String getTypeName() const { return getType().toString(); }
void setColumns(const NamesAndTypesList & new_columns);
const NamesAndTypesList & getColumns() const { return columns; }
void setSerializationInfos(const SerializationInfoByName & new_infos);
const SerializationInfoByName & getSerializationInfos() const { return serialization_infos; }
SerializationPtr getSerialization(const NameAndTypePair & column) const;
/// Throws an exception if part is not stored in on-disk format.
void assertOnDisk() const;
void remove() const;
void projectionRemove(const String & parent_to, bool keep_shared_data = false) const;
/// Initialize columns (from columns.txt if exists, or create from column files if not).
/// Load checksums from checksums.txt if exists. Load index if required.
void loadColumnsChecksumsIndexes(bool require_columns_checksums, bool check_consistency);
String getMarksFileExtension() const { return index_granularity_info.marks_file_extension; }
/// Generate the new name for this part according to `new_part_info` and min/max dates from the old name.
/// This is useful when you want to change e.g. block numbers or the mutation version of the part.
String getNewName(const MergeTreePartInfo & new_part_info) const;
/// Returns column position in part structure or std::nullopt if it's missing in part.
///
/// NOTE: Doesn't take column renames into account, if some column renames
/// take place, you must take original name of column for this part from
/// storage and pass it to this method.
std::optional<size_t> getColumnPosition(const String & column_name) const;
/// Returns the name of a column with minimum compressed size (as returned by getColumnSize()).
/// If no checksums are present returns the name of the first physically existing column.
String getColumnNameWithMinimumCompressedSize(const StorageMetadataPtr & metadata_snapshot) const;
bool contains(const IMergeTreeDataPart & other) const { return info.contains(other.info); }
/// If the partition key includes date column (a common case), this function will return min and max values for that column.
std::pair<DayNum, DayNum> getMinMaxDate() const;
/// otherwise, if the partition key includes dateTime column (also a common case), this function will return min and max values for that column.
std::pair<time_t, time_t> getMinMaxTime() const;
bool isEmpty() const { return rows_count == 0; }
/// Compute part block id for zero level part. Otherwise throws an exception.
String getZeroLevelPartBlockID() const;
const MergeTreeData & storage;
String name;
MergeTreePartInfo info;
/// Part unique identifier.
/// The intention is to use it for identifying cases where the same part is
/// processed by multiple shards.
UUID uuid = UUIDHelpers::Nil;
VolumePtr volume;
/// A directory path (relative to storage's path) where part data is actually stored
/// Examples: 'detached/tmp_fetch_<name>', 'tmp_<name>', '<name>'
/// NOTE: Cannot have trailing slash.
mutable String relative_path;
MergeTreeIndexGranularityInfo index_granularity_info;
size_t rows_count = 0;
time_t modification_time = 0;
/// When the part is removed from the working set. Changes once.
mutable std::atomic<time_t> remove_time { std::numeric_limits<time_t>::max() };
/// If true, the destructor will delete the directory with the part.
/// FIXME Why do we need this flag? What's difference from Temporary and DeleteOnDestroy state? Can we get rid of this?
bool is_temp = false;
/// If true it means that there are no ZooKeeper node for this part, so it should be deleted only from filesystem
bool is_duplicate = false;
/// Frozen by ALTER TABLE ... FREEZE ... It is used for information purposes in system.parts table.
mutable std::atomic<bool> is_frozen {false};
/// Flag for keep S3 data when zero-copy replication over S3 turned on.
mutable bool force_keep_shared_data = false;
/**
* Part state is a stage of its lifetime. States are ordered and state of a part could be increased only.
* Part state should be modified under data_parts mutex.
*
* Possible state transitions:
* Temporary -> PreActive: we are trying to add a fetched, inserted or merged part to active set
* PreActive -> Outdated: we could not add a part to active set and are doing a rollback (for example it is duplicated part)
* PreActive -> Active: we successfully added a part to active dataset
* PreActive -> Outdated: a part was replaced by a covering part or DROP PARTITION
* Outdated -> Deleting: a cleaner selected this part for deletion
* Deleting -> Outdated: if an ZooKeeper error occurred during the deletion, we will retry deletion
* Active -> DeleteOnDestroy: if part was moved to another disk
*/
enum class State
{
Temporary, /// the part is generating now, it is not in data_parts list
PreActive, /// the part is in data_parts, but not used for SELECTs
Active, /// active data part, used by current and upcoming SELECTs
Outdated, /// not active data part, but could be used by only current SELECTs, could be deleted after SELECTs finishes
Deleting, /// not active data part with identity refcounter, it is deleting right now by a cleaner
DeleteOnDestroy, /// part was moved to another disk and should be deleted in own destructor
};
using TTLInfo = MergeTreeDataPartTTLInfo;
using TTLInfos = MergeTreeDataPartTTLInfos;
TTLInfos ttl_infos;
/// Current state of the part. If the part is in working set already, it should be accessed via data_parts mutex
void setState(State new_state) const;
State getState() const;
static constexpr std::string_view stateString(State state) { return magic_enum::enum_name(state); }
constexpr std::string_view stateString() const { return stateString(state); }
String getNameWithState() const { return fmt::format("{} (state {})", name, stateString()); }
/// Returns true if state of part is one of affordable_states
bool checkState(const std::initializer_list<State> & affordable_states) const
{
for (auto affordable_state : affordable_states)
{
if (state == affordable_state)
return true;
}
return false;
}
/// Throws an exception if state of the part is not in affordable_states
void assertState(const std::initializer_list<State> & affordable_states) const;
/// Primary key (correspond to primary.idx file).
/// Always loaded in RAM. Contains each index_granularity-th value of primary key tuple.
/// Note that marks (also correspond to primary key) is not always in RAM, but cached. See MarkCache.h.
using Index = Columns;
Index index;
MergeTreePartition partition;
/// Amount of rows between marks
/// As index always loaded into memory
MergeTreeIndexGranularity index_granularity;
/// Index that for each part stores min and max values of a set of columns. This allows quickly excluding
/// parts based on conditions on these columns imposed by a query.
/// Currently this index is built using only columns required by partition expression, but in principle it
/// can be built using any set of columns.
struct MinMaxIndex
{
/// A direct product of ranges for each key column. See Storages/MergeTree/KeyCondition.cpp for details.
std::vector<Range> hyperrectangle;
bool initialized = false;
public:
MinMaxIndex() = default;
/// For month-based partitioning.
MinMaxIndex(DayNum min_date, DayNum max_date)
: hyperrectangle(1, Range(min_date, true, max_date, true))
, initialized(true)
{
}
using WrittenFiles = std::vector<std::unique_ptr<WriteBufferFromFileBase>>;
void load(const MergeTreeData & data, const DiskPtr & disk_, const String & part_path);
[[nodiscard]] WrittenFiles store(const MergeTreeData & data, const DiskPtr & disk_, const String & part_path, Checksums & checksums) const;
[[nodiscard]] WrittenFiles store(const Names & column_names, const DataTypes & data_types, const DiskPtr & disk_, const String & part_path, Checksums & checksums) const;
void update(const Block & block, const Names & column_names);
void merge(const MinMaxIndex & other);
};
using MinMaxIndexPtr = std::shared_ptr<MinMaxIndex>;
MinMaxIndexPtr minmax_idx;
Checksums checksums;
/// Columns with values, that all have been zeroed by expired ttl
NameSet expired_columns;
CompressionCodecPtr default_codec;
/// For data in RAM ('index')
UInt64 getIndexSizeInBytes() const;
UInt64 getIndexSizeInAllocatedBytes() const;
UInt64 getMarksCount() const;
UInt64 getBytesOnDisk() const { return bytes_on_disk; }
void setBytesOnDisk(UInt64 bytes_on_disk_) { bytes_on_disk = bytes_on_disk_; }
size_t getFileSizeOrZero(const String & file_name) const;
/// Returns path to part dir relatively to disk mount point
String getFullRelativePath() const;
/// Returns full path to part dir
String getFullPath() const;
/// Moves a part to detached/ directory and adds prefix to its name
void renameToDetached(const String & prefix) const;
/// Makes checks and move part to new directory
/// Changes only relative_dir_name, you need to update other metadata (name, is_temp) explicitly
virtual void renameTo(const String & new_relative_path, bool remove_new_dir_if_exists) const;
/// Cleanup shared locks made with old name after part renaming
virtual void cleanupOldName(const String & old_part_name) const;
/// Makes clone of a part in detached/ directory via hard links
virtual void makeCloneInDetached(const String & prefix, const StorageMetadataPtr & metadata_snapshot) const;
/// Makes full clone of part in specified subdirectory (relative to storage data directory, e.g. "detached") on another disk
void makeCloneOnDisk(const DiskPtr & disk, const String & directory_name) const;
/// Checks that .bin and .mrk files exist.
///
/// NOTE: Doesn't take column renames into account, if some column renames
/// take place, you must take original name of column for this part from
/// storage and pass it to this method.
virtual bool hasColumnFiles(const NameAndTypePair & /* column */) const { return false; }
/// Returns true if this part shall participate in merges according to
/// settings of given storage policy.
bool shallParticipateInMerges(const StoragePolicyPtr & storage_policy) const;
/// Calculate the total size of the entire directory with all the files
static UInt64 calculateTotalSizeOnDisk(const DiskPtr & disk_, const String & from);
/// Calculate column and secondary indices sizes on disk.
void calculateColumnsAndSecondaryIndicesSizesOnDisk();
String getRelativePathForPrefix(const String & prefix, bool detached = false) const;
bool isProjectionPart() const { return parent_part != nullptr; }
const IMergeTreeDataPart * getParentPart() const { return parent_part; }
const std::map<String, std::shared_ptr<IMergeTreeDataPart>> & getProjectionParts() const { return projection_parts; }
void addProjectionPart(const String & projection_name, std::shared_ptr<IMergeTreeDataPart> && projection_part)
{
projection_parts.emplace(projection_name, std::move(projection_part));
}
bool hasProjection(const String & projection_name) const
{
return projection_parts.find(projection_name) != projection_parts.end();
}
void loadProjections(bool require_columns_checksums, bool check_consistency);
/// Return set of metadata file names without checksums. For example,
/// columns.txt or checksums.txt itself.
NameSet getFileNamesWithoutChecksums() const;
/// File with compression codec name which was used to compress part columns
/// by default. Some columns may have their own compression codecs, but
/// default will be stored in this file.
static inline constexpr auto DEFAULT_COMPRESSION_CODEC_FILE_NAME = "default_compression_codec.txt";
static inline constexpr auto DELETE_ON_DESTROY_MARKER_FILE_NAME = "delete-on-destroy.txt";
static inline constexpr auto UUID_FILE_NAME = "uuid.txt";
/// File that contains information about kinds of serialization of columns
/// and information that helps to choose kind of serialization later during merging
/// (number of rows, number of rows with default values, etc).
static inline constexpr auto SERIALIZATION_FILE_NAME = "serialization.json";
/// Checks that all TTLs (table min/max, column ttls, so on) for part
/// calculated. Part without calculated TTL may exist if TTL was added after
/// part creation (using alter query with materialize_ttl setting).
bool checkAllTTLCalculated(const StorageMetadataPtr & metadata_snapshot) const;
/// Return some uniq string for file.
/// Required for distinguish different copies of the same part on remote FS.
String getUniqueId() const;
/// Return hardlink count for part.
/// Required for keep data on remote FS when part has shadow copies.
UInt32 getNumberOfRefereneces() const;
protected:
/// Total size of all columns, calculated once in calcuateColumnSizesOnDisk
ColumnSize total_columns_size;
/// Size for each column, calculated once in calcuateColumnSizesOnDisk
ColumnSizeByName columns_sizes;
ColumnSize total_secondary_indices_size;
IndexSizeByName secondary_index_sizes;
/// Total size on disk, not only columns. May not contain size of
/// checksums.txt and columns.txt. 0 - if not counted;
UInt64 bytes_on_disk{0};
/// Columns description. Cannot be changed, after part initialization.
NamesAndTypesList columns;
const Type part_type;
/// Not null when it's a projection part.
const IMergeTreeDataPart * parent_part;
std::map<String, std::shared_ptr<IMergeTreeDataPart>> projection_parts;
void removeIfNeeded();
virtual void checkConsistency(bool require_part_metadata) const;
void checkConsistencyBase() const;
/// Fill each_columns_size and total_size with sizes from columns files on
/// disk using columns and checksums.
virtual void calculateEachColumnSizes(ColumnSizeByName & each_columns_size, ColumnSize & total_size) const = 0;
String getRelativePathForDetachedPart(const String & prefix) const;
std::optional<bool> keepSharedDataInDecoupledStorage() const;
private:
/// In compact parts order of columns is necessary
NameToNumber column_name_to_position;
/// Map from name of column to its serialization info.
SerializationInfoByName serialization_infos;
/// Reads part unique identifier (if exists) from uuid.txt
void loadUUID();
/// Reads columns names and types from columns.txt
void loadColumns(bool require);
/// If checksums.txt exists, reads file's checksums (and sizes) from it
void loadChecksums(bool require);
/// Loads marks index granularity into memory
virtual void loadIndexGranularity();
/// Loads index file.
void loadIndex();
/// Load rows count for this part from disk (for the newer storage format version).
/// For the older format version calculates rows count from the size of a column with a fixed size.
void loadRowsCount();
/// Loads ttl infos in json format from file ttl.txt. If file doesn't exists assigns ttl infos with all zeros
void loadTTLInfos();
void loadPartitionAndMinMaxIndex();
void calculateColumnsSizesOnDisk();
void calculateSecondaryIndicesSizesOnDisk();
/// Load default compression codec from file default_compression_codec.txt
/// if it not exists tries to deduce codec from compressed column without
/// any specifial compression.
void loadDefaultCompressionCodec();
/// Found column without specific compression and return codec
/// for this column with default parameters.
CompressionCodecPtr detectDefaultCompressionCodec() const;
mutable State state{State::Temporary};
};
using MergeTreeDataPartState = IMergeTreeDataPart::State;
using MergeTreeDataPartPtr = std::shared_ptr<const IMergeTreeDataPart>;
using MergeTreeMutableDataPartPtr = std::shared_ptr<IMergeTreeDataPart>;
bool isCompactPart(const MergeTreeDataPartPtr & data_part);
bool isWidePart(const MergeTreeDataPartPtr & data_part);
bool isInMemoryPart(const MergeTreeDataPartPtr & data_part);
}