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#pragma once
#include <Databases/DatabasesCommon.h>
#include <Databases/DatabaseOrdinary.h>
namespace DB
{
/// All tables in DatabaseAtomic have persistent UUID and store data in
/// /clickhouse_path/store/xxx/xxxyyyyy-yyyy-yyyy-yyyy-yyyyyyyyyyyy/
/// where xxxyyyyy-yyyy-yyyy-yyyy-yyyyyyyyyyyy is UUID of the table.
/// RENAMEs are performed without changing UUID and moving table data.
/// Tables in Atomic databases can be accessed by UUID through DatabaseCatalog.
/// On DROP TABLE no data is removed, DatabaseAtomic just marks table as dropped
/// by moving metadata to /clickhouse_path/metadata_dropped/ and notifies DatabaseCatalog.
/// Running queries still may use dropped table. Table will be actually removed when it's not in use.
/// Allows to execute RENAME and DROP without IStorage-level RWLocks
class DatabaseAtomic : public DatabaseOrdinary
{
public:
DatabaseAtomic(String name_, String metadata_path_, UUID uuid, const String & logger_name, ContextPtr context_);
DatabaseAtomic(String name_, String metadata_path_, UUID uuid, ContextPtr context_);
String getEngineName() const override { return "Atomic"; }
UUID getUUID() const override { return db_uuid; }
void renameDatabase(ContextPtr query_context, const String & new_name) override;
void renameTable(
ContextPtr context,
const String & table_name,
IDatabase & to_database,
const String & to_table_name,
bool exchange,
bool dictionary) override;
void dropTable(ContextPtr context, const String & table_name, bool sync) override;
void dropTableImpl(ContextPtr context, const String & table_name, bool sync);
void attachTable(ContextPtr context, const String & name, const StoragePtr & table, const String & relative_table_path) override;
StoragePtr detachTable(ContextPtr context, const String & name) override;
String getTableDataPath(const String & table_name) const override;
String getTableDataPath(const ASTCreateQuery & query) const override;
void drop(ContextPtr /*context*/) override;
DatabaseTablesIteratorPtr getTablesIterator(ContextPtr context, const FilterByNameFunction & filter_by_table_name) const override;
void loadStoredObjects(ContextMutablePtr context, LoadingStrictnessLevel mode) override;
void beforeLoadingMetadata(ContextMutablePtr context, LoadingStrictnessLevel mode) override;
void startupTables(ThreadPool & thread_pool, LoadingStrictnessLevel mode) override;
/// Atomic database cannot be detached if there is detached table which still in use
void assertCanBeDetached(bool cleanup) override;
UUID tryGetTableUUID(const String & table_name) const override;
void tryCreateSymlink(const String & table_name, const String & actual_data_path, bool if_data_path_exist = false);
void tryRemoveSymlink(const String & table_name);
void waitDetachedTableNotInUse(const UUID & uuid) override;
void checkDetachedTableNotInUse(const UUID & uuid) override;
void setDetachedTableNotInUseForce(const UUID & uuid) override;
protected:
void commitAlterTable(const StorageID & table_id, const String & table_metadata_tmp_path, const String & table_metadata_path, const String & statement, ContextPtr query_context) override;
void commitCreateTable(const ASTCreateQuery & query, const StoragePtr & table,
const String & table_metadata_tmp_path, const String & table_metadata_path, ContextPtr query_context) override;
void assertDetachedTableNotInUse(const UUID & uuid) TSA_REQUIRES(mutex);
using DetachedTables = std::unordered_map<UUID, StoragePtr>;
[[nodiscard]] DetachedTables cleanupDetachedTables() TSA_REQUIRES(mutex);
void tryCreateMetadataSymlink();
virtual bool allowMoveTableToOtherDatabaseEngine(IDatabase & /*to_database*/) const { return false; }
//TODO store path in DatabaseWithOwnTables::tables
using NameToPathMap = std::unordered_map<String, String>;
NameToPathMap table_name_to_path TSA_GUARDED_BY(mutex);
DetachedTables detached_tables TSA_GUARDED_BY(mutex);
String path_to_table_symlinks;
String path_to_metadata_symlink;
const UUID db_uuid;
};
}
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