#include <sql_union.h>

Inheritance diagram for Query_result_union:

Public Member Functions
	Query_result_union ()

bool	prepare (THD thd, const mem_root_deque< Item > &list, Query_expression *u) override
	Perform preparation specific to the query expression or DML statement. More...

virtual bool	postponed_prepare (THD thd, const mem_root_deque< Item > &types)
	Do prepare() if preparation has been postponed until column type information is computed (used by Query_result_union_direct). More...

bool	send_data (THD thd, const mem_root_deque< Item > &items) override

bool	send_eof (THD *thd) override

virtual bool	flush ()

void	cleanup () override
	Cleanup after this execution. More...

bool	reset () override
	Reset and empty the temporary table that stores the materialized query result. More...

bool	create_result_table (THD thd, const mem_root_deque< Item > &column_types, bool is_distinct, ulonglong options, const char alias, bool bit_fields_as_long, bool create_table, Query_term_set_op op=nullptr)
	Create a temporary table to store the result of a query expression (used, among others, when materializing a UNION DISTINCT). More...

uint	get_hidden_field_count () const

bool	skip_create_table () const

void	set_limit (ha_rows limit_rows) override
	Set an effective LIMIT for the number of rows coming out of a materialized temporary table used for implementing INTERSECT or EXCEPT: informs TableScanIterator::TableScanIterator how many rows to read from the materialized table. More...

Public Member Functions inherited from Query_result_interceptor
	Query_result_interceptor ()

uint	field_count (const mem_root_deque< Item * > &) const override

bool	send_result_set_metadata (THD , const mem_root_deque< Item > &, uint) override

Public Member Functions inherited from Query_result
	Query_result ()

virtual	~Query_result ()=default

virtual bool	needs_file_privilege () const

virtual bool	change_query_result (THD , Query_result )
	Change wrapped Query_result. More...

virtual bool	need_explain_interceptor () const

virtual bool	start_execution (THD *)
	Prepare for execution of the query expression or DML statement. More...

virtual bool	create_table_for_query_block (THD *)
	Create table, only needed to support CREATE TABLE ... SELECT. More...

virtual bool	check_supports_cursor () const
	Check if this query result set supports cursors. More...

virtual void	abort_result_set (THD *)

virtual bool	use_protocol_adapter () const

virtual bool	use_protocol_wrapper () const

virtual Server_side_cursor *	cursor () const

Public Attributes
TABLE *	table

Public Attributes inherited from Query_result
ha_rows	estimated_rowcount
	Number of records estimated in this result. More...

double	estimated_cost
	Cost to execute the subquery which produces this result. More...

Protected Attributes
Temp_table_param	tmp_table_param

Protected Attributes inherited from Query_result
Query_expression *	unit

Friends
class	Common_table_expr

bool	Table_ref::create_materialized_table (THD *thd)

bool	Table_ref::optimize_derived (THD *thd)

Constructor & Destructor Documentation

◆ Query_result_union()

Query_result_union::Query_result_union ( )

inline

Member Function Documentation

◆ cleanup()

void Query_result_union::cleanup ( void )

inlineoverridevirtual

Cleanup after this execution.

Completes the execution and resets object before next execution of a prepared statement/stored procedure.

Reimplemented from Query_result.

◆ create_result_table()

bool Query_result_union::create_result_table	(	THD *	thd_arg,
		const mem_root_deque< Item * > &	column_types,
		bool	is_union_distinct,
		ulonglong	options,
		const char *	table_alias,
		bool	bit_fields_as_long,
		bool	create_table,
		Query_term_set_op *	op = `nullptr`
	)

Create a temporary table to store the result of a query expression (used, among others, when materializing a UNION DISTINCT).

Parameters

thd_arg	thread handle
column_types	a list of items used to define columns of the temporary table
is_union_distinct	if set, the temporary table will eliminate duplicates on insert
options	create options
table_alias	name of the temporary table
bit_fields_as_long	convert bit fields to ulonglong
create_table	If false, a table handler will not be created when creating the result table.
op	If we are creating a result table for a set operation, op should contain the relevant set operation's query term. In other cases, op should be nullptr.

Create a temporary table that is used to store the result of a UNION, derived table, or a materialized cursor.

Returns: false if table created, true if error

◆ flush()

bool Query_result_union::flush ( )

virtual

Reimplemented in Query_result_union_direct.

◆ get_hidden_field_count()

uint Query_result_union::get_hidden_field_count ( ) const

inline

◆ postponed_prepare()

virtual bool Query_result_union::postponed_prepare	(	THD *	thd,
		const mem_root_deque< Item * > &	types
	)

inlinevirtual

Do prepare() if preparation has been postponed until column type information is computed (used by Query_result_union_direct).

Parameters

thd	Thread handle
types	Column types

Returns: false on success, true on failure

Reimplemented in Query_result_union_direct.

◆ prepare()

bool Query_result_union::prepare	(	THD *	,
		const mem_root_deque< Item * > &	,
		Query_expression *	u
	)

overridevirtual

Perform preparation specific to the query expression or DML statement.

Returns: false if success, true if error

Reimplemented from Query_result.

◆ reset()

bool Query_result_union::reset ( void )

overridevirtual

Reset and empty the temporary table that stores the materialized query result.

Note: The cleanup performed here is exactly the same as for the two temp tables of JOIN - exec_tmp_table_[1 | 2].

Reimplemented from Query_result.

◆ send_data()

bool Query_result_union::send_data	(	THD *	thd,
		const mem_root_deque< Item * > &	items
	)

overridevirtual

Implements Query_result.

◆ send_eof()

bool Query_result_union::send_eof ( THD * thd )

overridevirtual

Implements Query_result.

◆ set_limit()

void Query_result_union::set_limit ( ha_rows limit_rows )

overridevirtual

Set an effective LIMIT for the number of rows coming out of a materialized temporary table used for implementing INTERSECT or EXCEPT: informs TableScanIterator::TableScanIterator how many rows to read from the materialized table.

For UNION and simple tables the limitation is enforced earlier, at materialize time, but this is not possible for INTERSECT and EXCEPT due to the use of cardinality counters.

Parameters

limit_rows the effective limit, or HA_POS_ERROR if none.

Reimplemented from Query_result.

◆ skip_create_table()

bool Query_result_union::skip_create_table ( ) const

inline

Friends And Related Function Documentation

◆ Common_table_expr

friend class Common_table_expr

friend

◆ Table_ref::create_materialized_table

bool Table_ref::create_materialized_table ( THD * thd )

friend

◆ Table_ref::optimize_derived

bool Table_ref::optimize_derived ( THD * thd )

friend

Member Data Documentation

◆ table

TABLE* Query_result_union::table

◆ tmp_table_param

Temp_table_param Query_result_union::tmp_table_param

protected

The documentation for this class was generated from the following files:

sql/sql_union.h
sql/sql_union.cc

Public Member Functions

Public Attributes

Protected Attributes

Friends

Constructor & Destructor Documentation

◆ Query_result_union()

Member Function Documentation

◆ cleanup()

◆ create_result_table()

◆ flush()

◆ get_hidden_field_count()

◆ postponed_prepare()

◆ prepare()

◆ reset()

◆ send_data()

◆ send_eof()

◆ set_limit()

◆ skip_create_table()

Friends And Related Function Documentation

◆ Common_table_expr

◆ Table_ref::create_materialized_table

◆ Table_ref::optimize_derived

Member Data Documentation

◆ table

◆ tmp_table_param