#ifndef SQL_TRUNCATE_INCLUDED #define SQL_TRUNCATE_INCLUDED /* Copyright (c) 2010, 2014, Oracle and/or its affiliates. All rights reserved. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; version 2 of the License. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335 USA */ class THD; struct TABLE_LIST; /** Sql_cmd_truncate_table represents the TRUNCATE statement. */ class Sql_cmd_truncate_table : public Sql_cmd { private: /* Set if a lock must be downgraded after truncate is done. */ MDL_ticket *m_ticket_downgrade; public: /** Constructor, used to represent a TRUNCATE statement. */ Sql_cmd_truncate_table() = default; virtual ~Sql_cmd_truncate_table() = default; /** Execute a TRUNCATE statement at runtime. @param thd the current thread. @return false on success. */ bool execute(THD *thd) override; enum_sql_command sql_command_code() const override { return SQLCOM_TRUNCATE; } protected: enum truncate_result{ TRUNCATE_OK=0, TRUNCATE_FAILED_BUT_BINLOG, TRUNCATE_FAILED_SKIP_BINLOG }; /** Handle locking a base table for truncate. */ bool lock_table(THD *, TABLE_LIST *, bool *); /** Truncate table via the handler method. */ enum truncate_result handler_truncate(THD *, TABLE_LIST *, bool); /** Optimized delete of all rows by doing a full regenerate of the table. Depending on the storage engine, it can be accomplished through a drop and recreate or via the handler truncate method. */ bool truncate_table(THD *, TABLE_LIST *); }; #endif