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My Project
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My Project
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#include <sql_executor.h>
Public Types | |
| enum | enum_op_type { OT_CACHE, OT_TMP_TABLE } |
Public Member Functions | |
| QEP_operation (JOIN_TAB *tab) | |
| virtual enum_op_type | type ()=0 |
| virtual int | init () |
| virtual enum_nested_loop_state | put_record ()=0 |
| virtual enum_nested_loop_state | end_send ()=0 |
| virtual void | free () |
Public Attributes | |
| JOIN_TAB * | join_tab |
QEP_operation is an interface class for operations in query execution plan.
Currently following operations are implemented: JOIN_CACHE - caches partial join result and joins with attached table QEP_tmp_table - materializes join result in attached table
An operation's life cycle is as follows: .) it is initialized on the init() call .) accumulates records one by one when put_record() is called. .) finalize record sending when end_send() is called. .) free all internal buffers on the free() call.
Each operation is attached to a join_tab, to which exactly depends on the operation type: JOIN_CACHE is attached to the table following the table being cached, QEP_tmp_buffer is attached to a tmp table.
| virtual enum_nested_loop_state QEP_operation::end_send | ( | ) | [pure virtual] |
Finalize records sending.
Implemented in JOIN_CACHE, and QEP_tmp_table.
| virtual void QEP_operation::free | ( | ) | [inline, virtual] |
Internal state cleanup.
Reimplemented in JOIN_CACHE.
| virtual int QEP_operation::init | ( | void | ) | [inline, virtual] |
Initialize operation's internal state. Called once per query execution.
Reimplemented in JOIN_CACHE_BKA_UNIQUE, JOIN_CACHE_BKA, JOIN_CACHE_BNL, and JOIN_CACHE.
| virtual enum_nested_loop_state QEP_operation::put_record | ( | ) | [pure virtual] |
Put a new record into the operation's buffer
Implemented in JOIN_CACHE, and QEP_tmp_table.
For JOIN_CACHE : Table to be joined with the partial join records from the cache For JOIN_TMP_BUFFER : join_tab of tmp table
1.7.6.1
