Query_result_materialize – a mediator between a cursor query and the protocol. More...

Inheritance diagram for Query_result_materialize:

Public Member Functions
	Query_result_materialize (Query_result *result_arg)

	~Query_result_materialize () override

void	set_result (Query_result *result_arg)

bool	check_simple_query_block () const override
	Check if this query returns a result set and therefore is allowed in cursors and set an error message if it is not the case. More...

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...

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

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

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

Public Member Functions inherited from Query_result_union
	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[[maybe_unused]], const mem_root_deque< Item > &types[[maybe_unused]])
	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 (THD *) 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)
	Create a temporary table to store the result of a query expression (used, among others, when materializing a UNION DISTINCT). More...

const ha_rows *	row_count () const override

Public Member Functions inherited from Query_result_interceptor
	Query_result_interceptor ()

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

bool	is_interceptor () const final
	Checks if this Query_result intercepts and transforms the result set. More...

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	optimize ()
	Optimize the result processing of a query expression, applicable to data change operation (not simple select queries). More...

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

virtual void	send_error (THD , uint errcode, const char err)

virtual void	abort_result_set (THD *)

void	begin_dataset ()

virtual bool	immediate_update (TABLE_LIST *t[[maybe_unused]]) const
	If this Query_result performs modifications to tables: tells if it modifies the given table's row as it's read (a.k.a. More...

Public Attributes
Materialized_cursor *	materialized_cursor

Public Attributes inherited from Query_result_union
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...

Private Attributes
Query_result *	result
	the result object of the caller (PS or SP) More...

Additional Inherited Members
Protected Attributes inherited from Query_result_union
Temp_table_param	tmp_table_param

ha_rows	m_rows_in_table
	Count of rows successfully stored in tmp table. More...

Protected Attributes inherited from Query_result
Query_expression *	unit

Detailed Description

Query_result_materialize – a mediator between a cursor query and the protocol.

In case we were not able to open a non-materialzed cursor, it creates an internal temporary memory table, and inserts all rows into it. If the table is in the Heap engine and if it reaches maximum Heap table size, it's converted to a disk-based temporary table. Later this table is used to create a Materialized_cursor.

Constructor & Destructor Documentation

◆ Query_result_materialize()

Query_result_materialize::Query_result_materialize ( Query_result * result_arg )

inline

◆ ~Query_result_materialize()

Query_result_materialize::~Query_result_materialize ( )

inlineoverride

Member Function Documentation

◆ check_simple_query_block()

bool Query_result_materialize::check_simple_query_block ( ) const

inlineoverridevirtual

Check if this query returns a result set and therefore is allowed in cursors and set an error message if it is not the case.

Return values

false	success
true	error, an error message is set

Reimplemented from Query_result.

◆ cleanup()

void Query_result_materialize::cleanup ( THD * )

inlineoverridevirtual

Cleanup after this execution.

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

Reimplemented from Query_result.

◆ prepare()

bool Query_result_materialize::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.

◆ send_result_set_metadata()

bool Query_result_materialize::send_result_set_metadata	(	THD *	thd,
		const mem_root_deque< Item * > &	list,
		uint	flags
	)

overridevirtual

Reimplemented from Query_result_interceptor.

◆ set_result()

void Query_result_materialize::set_result ( Query_result * result_arg )

inline

◆ start_execution()

bool Query_result_materialize::start_execution ( THD * )

overridevirtual

Prepare for execution of the query expression or DML statement.

Generally, this will have an implementation only for outer-most Query_block objects, such as data change statements (for preparation of the target table(s)) or dump statements (for preparation of target file).

Returns: false if success, true if error

Reimplemented from Query_result.

Member Data Documentation

◆ materialized_cursor

Materialized_cursor* Query_result_materialize::materialized_cursor

◆ result

Query_result* Query_result_materialize::result

private

the result object of the caller (PS or SP)

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

sql/sql_cursor.cc

Public Member Functions

Public Attributes

Private Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ Query_result_materialize()

◆ ~Query_result_materialize()

Member Function Documentation

◆ check_simple_query_block()

◆ cleanup()

◆ prepare()

◆ send_result_set_metadata()

◆ set_result()

◆ start_execution()

Member Data Documentation

◆ materialized_cursor

◆ result