ClickHouse/dbms/src/Interpreters/InterpreterAlterQuery.h

130 lines
3.6 KiB
C++

#pragma once
#include <Storages/IStorage.h>
#include <Storages/AlterCommands.h>
#include <Interpreters/Context.h>
#include <Interpreters/IInterpreter.h>
#include <Parsers/ASTAlterQuery.h>
namespace DB
{
/** Allows you add or remove a column in the table.
* It also allows you to manipulate the partitions of the MergeTree family tables.
*/
class InterpreterAlterQuery : public IInterpreter
{
public:
InterpreterAlterQuery(const ASTPtr & query_ptr_, const Context & context_);
BlockIO execute() override;
private:
struct PartitionCommand
{
enum Type
{
DROP_PARTITION,
ATTACH_PARTITION,
FETCH_PARTITION,
FREEZE_PARTITION,
RESHARD_PARTITION,
CLEAR_COLUMN,
};
Type type;
Field partition;
Field column_name;
bool detach = false; /// true for DETACH PARTITION.
bool part = false;
String from; /// For FETCH PARTITION - path in ZK to the shard, from which to download the partition.
/// For RESHARD PARTITION.
WeightedZooKeeperPaths weighted_zookeeper_paths;
ASTPtr sharding_key_expr;
bool do_copy = false;
Field coordinator;
/// For FREEZE PARTITION
String with_name;
static PartitionCommand dropPartition(const Field & partition, bool detach)
{
PartitionCommand res;
res.type = DROP_PARTITION;
res.partition = partition;
res.detach = detach;
return res;
}
static PartitionCommand clearColumn(const Field & partition, const Field & column_name)
{
PartitionCommand res;
res.type = CLEAR_COLUMN;
res.partition = partition;
res.column_name = column_name;
return res;
}
static PartitionCommand attachPartition(const Field & partition, bool part)
{
PartitionCommand res;
res.type = ATTACH_PARTITION;
res.partition = partition;
res.part = part;
return res;
}
static PartitionCommand fetchPartition(const Field & partition, const String & from)
{
PartitionCommand res;
res.type = FETCH_PARTITION;
res.partition = partition;
res.from = from;
return res;
}
static PartitionCommand freezePartition(const Field & partition, const String & with_name)
{
PartitionCommand res;
res.type = FREEZE_PARTITION;
res.partition = partition;
res.with_name = with_name;
return res;
}
static PartitionCommand reshardPartitions(const Field & partition_,
const WeightedZooKeeperPaths & weighted_zookeeper_paths_, const ASTPtr & sharding_key_expr_,
bool do_copy_, const Field & coordinator_)
{
PartitionCommand res;
res.type = RESHARD_PARTITION;
res.partition = partition_;
res.weighted_zookeeper_paths = weighted_zookeeper_paths_;
res.sharding_key_expr = sharding_key_expr_;
res.do_copy = do_copy_;
res.coordinator = coordinator_;
return res;
}
};
class PartitionCommands : public std::vector<PartitionCommand>
{
public:
void validate(const IStorage * table);
};
ASTPtr query_ptr;
const Context & context;
static void parseAlter(const ASTAlterQuery::ParameterContainer & params,
AlterCommands & out_alter_commands, PartitionCommands & out_partition_commands);
};
}