QEP_tmp_table Class Reference

Class for accumulating join result in a tmp table, grouping them if necessary, and sending further. More...

#include <sql_executor.h>

Inheritance diagram for QEP_tmp_table:

List of all members.

Public Member Functions
	QEP_tmp_table (JOIN_TAB *tab)
enum_op_type	type ()
enum_nested_loop_state	put_record ()
enum_nested_loop_state	end_send ()
	Finish rnd/index scan after accumulating records, switch ref_array, and send accumulated records further.
void	set_write_func (Next_select_func new_write_func)

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Detailed Description

Class for accumulating join result in a tmp table, grouping them if necessary, and sending further.

Join result records are accumulated on the put_record() call. The accumulation process is determined by the write_func, it could be: end_write Simply store all records in tmp table. end_write_group Perform grouping using join->group_fields, records are expected to be sorted. end_update Perform grouping using the key generated on tmp table. Input records aren't expected to be sorted. Tmp table uses the heap engine end_update_unique Same as above, but the engine is myisam.

Lazy table initialization is used - the table will be instantiated and rnd/index scan started on the first put_record() call.

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Member Function Documentation

enum_nested_loop_state QEP_tmp_table::put_record

(

)

[inline, virtual]

Put a new record into the operation's buffer

Returns:

return one of enum_nested_loop_state values.

Implements QEP_operation.

void QEP_tmp_table::set_write_func

(

Next_select_func

new_write_func

)

[inline]

write_func setter

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

• sql_executor.h
• sql_executor.cc