ClickHouse/src/Interpreters/InterpreterDeleteQuery.cpp
2022-07-26 11:50:09 +08:00

106 lines
4.3 KiB
C++

#include <Interpreters/InterpreterDeleteQuery.h>
#include <Access/ContextAccess.h>
#include <Databases/DatabaseReplicated.h>
#include <Databases/IDatabase.h>
#include <Interpreters/Context.h>
#include <Interpreters/FunctionNameNormalizer.h>
#include <Interpreters/MutationsInterpreter.h>
#include <Parsers/ASTDeleteQuery.h>
#include <Parsers/ASTAssignment.h>
#include <Parsers/ASTExpressionList.h>
#include <Storages/AlterCommands.h>
#include <Storages/IStorage.h>
#include <Storages/MutationCommands.h>
#include <Storages/StorageMergeTree.h>
#include <Storages/StorageReplicatedMergeTree.h>
#include <Storages/LightweightDeleteDescription.h>
namespace DB
{
namespace ErrorCodes
{
extern const int BAD_ARGUMENTS;
extern const int TABLE_IS_READ_ONLY;
extern const int SUPPORT_IS_DISABLED;
}
InterpreterDeleteQuery::InterpreterDeleteQuery(const ASTPtr & query_ptr_, ContextPtr context_) : WithContext(context_), query_ptr(query_ptr_)
{
}
BlockIO InterpreterDeleteQuery::execute()
{
if (!getContext()->getSettingsRef().allow_experimental_lightweight_delete)
{
throw Exception(ErrorCodes::SUPPORT_IS_DISABLED, "Lightweight delete mutate is experimental. Set `allow_experimental_lightweight_delete` setting to enable it");
}
FunctionNameNormalizer().visit(query_ptr.get());
const ASTDeleteQuery & delete_query = query_ptr->as<ASTDeleteQuery &>();
auto table_id = getContext()->resolveStorageID(delete_query, Context::ResolveOrdinary);
getContext()->checkAccess(AccessType::ALTER_DELETE, table_id);
query_ptr->as<ASTDeleteQuery &>().setDatabase(table_id.database_name);
/// First check table storage for validations.
StoragePtr table = DatabaseCatalog::instance().getTable(table_id, getContext());
auto storage_merge_tree = std::dynamic_pointer_cast<StorageMergeTree>(table);
auto storage_replicated_merge_tree = std::dynamic_pointer_cast<StorageReplicatedMergeTree>(table);
if (!storage_merge_tree && !storage_replicated_merge_tree)
throw Exception(ErrorCodes::BAD_ARGUMENTS, "Only MergeTree or ReplicatedMergeTree tables are supported");
checkStorageSupportsTransactionsIfNeeded(table, getContext());
if (table->isStaticStorage())
throw Exception(ErrorCodes::TABLE_IS_READ_ONLY, "Table is read-only");
DatabasePtr database = DatabaseCatalog::instance().getDatabase(table_id.database_name);
if (typeid_cast<DatabaseReplicated *>(database.get())
&& !getContext()->getClientInfo().is_replicated_database_internal)
{
auto guard = DatabaseCatalog::instance().getDDLGuard(table_id.database_name, table_id.table_name);
guard->releaseTableLock();
return typeid_cast<DatabaseReplicated *>(database.get())->tryEnqueueReplicatedDDL(query_ptr, getContext());
}
auto table_lock = table->lockForShare(getContext()->getCurrentQueryId(), getContext()->getSettingsRef().lock_acquire_timeout);
auto metadata_snapshot = table->getInMemoryMetadataPtr();
/// Convert to MutationCommand
MutationCommands mutation_commands;
MutationCommand mut_command;
/// Build "UPDATE _row_exists = 0 WHERE predicate" query
mut_command.type = MutationCommand::Type::UPDATE;
mut_command.predicate = delete_query.predicate;
auto command = std::make_shared<ASTAlterCommand>();
command->type = ASTAlterCommand::UPDATE;
command->predicate = delete_query.predicate;
command->update_assignments = std::make_shared<ASTExpressionList>();
auto set_row_does_not_exist = std::make_shared<ASTAssignment>();
set_row_does_not_exist->column_name = LightweightDeleteDescription::FILTER_COLUMN.name;
auto zero_value = std::make_shared<ASTLiteral>(DB::Field(UInt8(0)));
set_row_does_not_exist->children.push_back(zero_value);
command->update_assignments->children.push_back(set_row_does_not_exist);
command->children.push_back(command->predicate);
command->children.push_back(command->update_assignments);
mut_command.column_to_update_expression[set_row_does_not_exist->column_name] = zero_value;
mut_command.ast = command->ptr();
mutation_commands.emplace_back(mut_command);
table->checkMutationIsPossible(mutation_commands, getContext()->getSettingsRef());
MutationsInterpreter(table, metadata_snapshot, mutation_commands, getContext(), false).validate();
table->mutate(mutation_commands, getContext());
return {};
}
}