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/* Copyright (c) 2010, 2014, Oracle and/or its affiliates.
Copyright (c) 2013, 2020, MariaDB Corporation.
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 */
#ifndef SQL_ALTER_TABLE_H
#define SQL_ALTER_TABLE_H
class Alter_drop;
class Alter_column;
class Key;
/**
Data describing the table being created by CREATE TABLE or
altered by ALTER TABLE.
*/
class Alter_info
{
public:
enum enum_enable_or_disable { LEAVE_AS_IS, ENABLE, DISABLE };
bool vers_prohibited(THD *thd) const;
/**
The different values of the ALGORITHM clause.
Describes which algorithm to use when altering the table.
*/
enum enum_alter_table_algorithm
{
/*
Use thd->variables.alter_algorithm for alter method. If this is also
default then use the fastest possible ALTER TABLE method
(INSTANT, NOCOPY, INPLACE, COPY)
*/
ALTER_TABLE_ALGORITHM_DEFAULT,
// Copy if supported, error otherwise.
ALTER_TABLE_ALGORITHM_COPY,
// In-place if supported, error otherwise.
ALTER_TABLE_ALGORITHM_INPLACE,
// No Copy will refuse any operation which does rebuild.
ALTER_TABLE_ALGORITHM_NOCOPY,
// Instant should allow any operation that changes metadata only.
ALTER_TABLE_ALGORITHM_INSTANT,
// When there is no specification of algorithm during alter table.
ALTER_TABLE_ALGORITHM_NONE
};
/**
The different values of the LOCK clause.
Describes the level of concurrency during ALTER TABLE.
*/
enum enum_alter_table_lock
{
// Maximum supported level of concurency for the given operation.
ALTER_TABLE_LOCK_DEFAULT,
// Allow concurrent reads & writes. If not supported, give error.
ALTER_TABLE_LOCK_NONE,
// Allow concurrent reads only. If not supported, give error.
ALTER_TABLE_LOCK_SHARED,
// Block reads and writes.
ALTER_TABLE_LOCK_EXCLUSIVE
};
// Columns and keys to be dropped.
List<Alter_drop> drop_list;
// Columns for ALTER_CHANGE_COLUMN_DEFAULT.
List<Alter_column> alter_list;
// List of keys, used by both CREATE and ALTER TABLE.
List<Key> key_list;
// List of columns, used by both CREATE and ALTER TABLE.
List<Create_field> create_list;
enum flags_bits
{
CHECK_CONSTRAINT_IF_NOT_EXISTS= 1
};
List<Virtual_column_info> check_constraint_list;
// Type of ALTER TABLE operation.
alter_table_operations flags;
ulong partition_flags;
// Enable or disable keys.
enum_enable_or_disable keys_onoff;
// List of partitions.
List<const char> partition_names;
// Number of partitions.
uint num_parts;
private:
// Type of ALTER TABLE algorithm.
enum_alter_table_algorithm requested_algorithm;
public:
// Type of ALTER TABLE lock.
enum_alter_table_lock requested_lock;
Alter_info() :
flags(0), partition_flags(0),
keys_onoff(LEAVE_AS_IS),
num_parts(0),
requested_algorithm(ALTER_TABLE_ALGORITHM_NONE),
requested_lock(ALTER_TABLE_LOCK_DEFAULT)
{}
void reset()
{
drop_list.empty();
alter_list.empty();
key_list.empty();
create_list.empty();
check_constraint_list.empty();
flags= 0;
partition_flags= 0;
keys_onoff= LEAVE_AS_IS;
num_parts= 0;
partition_names.empty();
requested_algorithm= ALTER_TABLE_ALGORITHM_NONE;
requested_lock= ALTER_TABLE_LOCK_DEFAULT;
}
/**
Construct a copy of this object to be used for mysql_alter_table
and mysql_create_table.
Historically, these two functions modify their Alter_info
arguments. This behaviour breaks re-execution of prepared
statements and stored procedures and is compensated by always
supplying a copy of Alter_info to these functions.
@param rhs Alter_info to make copy of
@param mem_root Mem_root for new Alter_info
@note You need to use check the error in THD for out
of memory condition after calling this function.
*/
Alter_info(const Alter_info &rhs, MEM_ROOT *mem_root);
/**
Parses the given string and sets requested_algorithm
if the string value matches a supported value.
Supported values: INPLACE, COPY, DEFAULT
@param str String containing the supplied value
@retval false Supported value found, state updated
@retval true Not supported value, no changes made
*/
bool set_requested_algorithm(const LEX_CSTRING *str);
/**
Parses the given string and sets requested_lock
if the string value matches a supported value.
Supported values: NONE, SHARED, EXCLUSIVE, DEFAULT
@param str String containing the supplied value
@retval false Supported value found, state updated
@retval true Not supported value, no changes made
*/
bool set_requested_lock(const LEX_CSTRING *str);
/**
Set the requested algorithm to the given algorithm value
@param algo_value algorithm to be set
*/
void set_requested_algorithm(enum_alter_table_algorithm algo_value);
/**
Returns the algorithm value in the format "algorithm=value"
*/
const char* algorithm_clause(THD *thd) const;
/**
Returns the lock value in the format "lock=value"
*/
const char* lock() const;
/**
Check whether the given result can be supported
with the specified user alter algorithm.
@param thd Thread handle
@param ha_alter_info Structure describing changes to be done
by ALTER TABLE and holding data during
in-place alter
@retval false Supported operation
@retval true Not supported value
*/
bool supports_algorithm(THD *thd,
const Alter_inplace_info *ha_alter_info);
/**
Check whether the given result can be supported
with the specified user lock type.
@param ha_alter_info Structure describing changes to be done
by ALTER TABLE and holding data during
in-place alter
@retval false Supported lock type
@retval true Not supported value
*/
bool supports_lock(THD *thd, const Alter_inplace_info *ha_alter_info);
/**
Return user requested algorithm. If user does not specify
algorithm then return alter_algorithm variable value.
*/
enum_alter_table_algorithm algorithm(const THD *thd) const;
private:
Alter_info &operator=(const Alter_info &rhs); // not implemented
Alter_info(const Alter_info &rhs); // not implemented
};
/** Runtime context for ALTER TABLE. */
class Alter_table_ctx
{
public:
Alter_table_ctx();
Alter_table_ctx(THD *thd, TABLE_LIST *table_list, uint tables_opened_arg,
const LEX_CSTRING *new_db_arg, const LEX_CSTRING *new_name_arg);
/**
@return true if the table is moved to another database, false otherwise.
*/
bool is_database_changed() const
{ return (new_db.str != db.str); };
/**
@return true if the table is renamed, false otherwise.
*/
bool is_table_renamed() const
{ return (is_database_changed() || new_name.str != table_name.str); };
/**
@return filename (including .frm) for the new table.
*/
const char *get_new_filename() const
{
DBUG_ASSERT(!tmp_table);
return new_filename;
}
/**
@return path to the original table.
*/
const char *get_path() const
{
DBUG_ASSERT(!tmp_table);
return path;
}
/**
@return path to the new table.
*/
const char *get_new_path() const
{
DBUG_ASSERT(!tmp_table);
return new_path;
}
/**
@return path to the temporary table created during ALTER TABLE.
*/
const char *get_tmp_path() const
{ return tmp_path; }
/**
Mark ALTER TABLE as needing to produce foreign key error if
it deletes a row from the table being changed.
*/
void set_fk_error_if_delete_row(FOREIGN_KEY_INFO *fk)
{
fk_error_if_delete_row= true;
fk_error_id= fk->foreign_id->str;
fk_error_table= fk->foreign_table->str;
}
public:
Create_field *datetime_field;
bool error_if_not_empty;
uint tables_opened;
LEX_CSTRING db;
LEX_CSTRING table_name;
LEX_CSTRING alias;
LEX_CSTRING new_db;
LEX_CSTRING new_name;
LEX_CSTRING new_alias;
LEX_CSTRING tmp_name;
char tmp_buff[80];
/**
Indicates that if a row is deleted during copying of data from old version
of table to the new version ER_FK_CANNOT_DELETE_PARENT error should be
emitted.
*/
bool fk_error_if_delete_row;
/** Name of foreign key for the above error. */
const char *fk_error_id;
/** Name of table for the above error. */
const char *fk_error_table;
bool modified_primary_key;
private:
char new_filename[FN_REFLEN + 1];
char new_alias_buff[NAME_LEN + 1];
char tmp_name_buff[NAME_LEN + 1];
char path[FN_REFLEN + 1];
char new_path[FN_REFLEN + 1];
char tmp_path[FN_REFLEN + 1];
#ifdef DBUG_ASSERT_EXISTS
/** Indicates that we are altering temporary table. Used only in asserts. */
bool tmp_table;
#endif
Alter_table_ctx &operator=(const Alter_table_ctx &rhs); // not implemented
Alter_table_ctx(const Alter_table_ctx &rhs); // not implemented
};
/**
Sql_cmd_common_alter_table represents the common properties of the ALTER TABLE
statements.
@todo move Alter_info and other ALTER generic structures from Lex here.
*/
class Sql_cmd_common_alter_table : public Sql_cmd
{
protected:
/**
Constructor.
*/
Sql_cmd_common_alter_table()
{}
virtual ~Sql_cmd_common_alter_table()
{}
virtual enum_sql_command sql_command_code() const
{
return SQLCOM_ALTER_TABLE;
}
};
/**
Sql_cmd_alter_table represents the generic ALTER TABLE statement.
@todo move Alter_info and other ALTER specific structures from Lex here.
*/
class Sql_cmd_alter_table : public Sql_cmd_common_alter_table,
public Storage_engine_name
{
public:
/**
Constructor, used to represent a ALTER TABLE statement.
*/
Sql_cmd_alter_table()
{}
~Sql_cmd_alter_table()
{}
Storage_engine_name *option_storage_engine_name() { return this; }
bool execute(THD *thd);
};
/**
Sql_cmd_alter_sequence represents the ALTER SEQUENCE statement.
*/
class Sql_cmd_alter_sequence : public Sql_cmd,
public DDL_options
{
public:
/**
Constructor, used to represent a ALTER TABLE statement.
*/
Sql_cmd_alter_sequence(const DDL_options &options)
:DDL_options(options)
{}
~Sql_cmd_alter_sequence()
{}
enum_sql_command sql_command_code() const
{
return SQLCOM_ALTER_SEQUENCE;
}
bool execute(THD *thd);
};
/**
Sql_cmd_alter_table_tablespace represents ALTER TABLE
IMPORT/DISCARD TABLESPACE statements.
*/
class Sql_cmd_discard_import_tablespace : public Sql_cmd_common_alter_table
{
public:
enum enum_tablespace_op_type
{
DISCARD_TABLESPACE, IMPORT_TABLESPACE
};
Sql_cmd_discard_import_tablespace(enum_tablespace_op_type tablespace_op_arg)
: m_tablespace_op(tablespace_op_arg)
{}
bool execute(THD *thd);
private:
const enum_tablespace_op_type m_tablespace_op;
};
#endif
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