2015/05/26 更新 今天又遇到了类似问题。。。尼玛无语了 编码规范啊 ！！！
今天有个兄弟跟我说sql跑得太慢了，让我看看。sql如下：
SELECT rownum row_num,
pv.vendor_name,
pha.segment1 po_num,
prh.preparer_id,
pha.Org_Id,
pha.po_header_id,
wo.department_code,
wo.description oper_seq_desc,
to_char(pha.creation_date, 'RRRR-MM-DD HH24:MI:SS') enter_date,
to_char(pha.approved_date, 'RRRR-MM-DD HH24:MI:SS') approved_date,
--cux_public_pkg.get_item_no(wdj.primary_item_id) item_no,
we.wip_entity_name
FROM PO.po_headers_all pha,
APPS.po_vendors pv,
PO.po_lines_all pla,
PO.po_line_locations_all pll,
PO.po_distributions_all pld,
PO.po_requisition_headers_all prh,
PO.po_requisition_lines_all prl,
PO.po_req_distributions_all prd,
WIP.wip_discrete_jobs wdj,
APPS.BOM_STANDARD_OPERATIONS_V bso,
APPS.wip_operations_v wo,
WIP.wip_entities we
WHERE 1 = 1
AND prl.wip_entity_id = we.wip_entity_id
AND pha.po_header_id = pla.po_header_id
AND pha.vendor_id = pv.vendor_id
AND pll.po_line_id = pla.po_line_id
AND pll.po_header_id = pha.po_header_id
AND pll.line_location_id = pld.line_location_id
AND prd.requisition_line_id = prl.requisition_line_id
AND pld.req_distribution_id = prd.distribution_id
AND prl.requisition_header_id = prh.requisition_header_id
AND prl.wip_entity_id = wdj.wip_entity_id
AND prl.wip_entity_id = wo.wip_entity_id
AND prl.wip_operation_seq_num = wo.operation_seq_num
AND wo.standard_operation_id = bso.STANDARD_OPERATION_ID
AND wdj.Organization_Id = /*p_organization_id*/83
AND pha.segment1 >= /*nvl(p_po_num_f, pha.segment1)*/'621337540'
AND pha.segment1 <= /*nvl(p_po_num_t, pha.segment1)*/ '621337540'
AND nvl(pha.approved_date, SYSDATE + 9999) >= nvl(pha.approved_date, SYSDATE + 9999)
AND nvl(pha.approved_date, SYSDATE + 9999) <=nvl(pha.approved_date, SYSDATE + 9999)
ORDER BY pha.segment1, pla.line_num;快速的运用sql三段分拆方法(分享过的) 扫描一下，发现没问题 (如果不知道的哥们，请自己百度 落落 sql 三段分拆方法)
SQL里面有个视图wo 视图代码如下：
/*CREATE OR REPLACE VIEW WIP_OPERATIONS_V
(row_id, wip_entity_id, operation_seq_num, organization_id, repetitive_schedule_id, last_update_date, last_updated_by, creation_date, created_by, last_update_login, request_id, program_application_id, program_id, program_update_date, operation_sequence_id, standard_operation_id, operation_code, department_id, department_code, location_id, description, scheduled_quantity, quantity_in_queue, quantity_running, quantity_waiting_to_move, quantity_rejected, quantity_scrapped, quantity_completed, first_unit_start_date, first_unit_completion_date, last_unit_start_date, last_unit_completion_date, previous_operation_seq_num, next_operation_seq_num, count_point_type, count_point_flag, autocharge_flag, backflush_flag, minimum_transfer_quantity, date_last_moved, attribute_category, attribute1, attribute2, attribute3, attribute4, attribute5, attribute6, attribute7, attribute8, attribute9, attribute10, attribute11, attribute12, attribute13, attribute14, attribute15, operation_yield, cumulative_scrap_quantity, operation_yield_enabled, operation_completed, shutdown_type, shutdown_type_disp, x_pos, y_pos, long_description, disable_date, recommended, progress_percentage, wsm_bonus_quantity, actual_start_date, actual_completion_date, employee_id, employee_name, lowest_acceptable_yield, check_skill)
AS*/
SELECT WO.ROWID ROW_ID,
WO.WIP_ENTITY_ID,
WO.OPERATION_SEQ_NUM,
WO.ORGANIZATION_ID,
WO.REPETITIVE_SCHEDULE_ID,
WO.LAST_UPDATE_DATE,
WO.LAST_UPDATED_BY,
WO.CREATION_DATE,
WO.CREATED_BY,
WO.LAST_UPDATE_LOGIN,
WO.REQUEST_ID,
WO.PROGRAM_APPLICATION_ID,
WO.PROGRAM_ID,
WO.PROGRAM_UPDATE_DATE,
WO.OPERATION_SEQUENCE_ID,
WO.STANDARD_OPERATION_ID,
BSO.OPERATION_CODE,
WO.DEPARTMENT_ID,
BD.DEPARTMENT_CODE,
BD.LOCATION_ID,
WO.DESCRIPTION,
WO.SCHEDULED_QUANTITY,
DECODE(WO.QUANTITY_IN_QUEUE, 0, NULL, WO.QUANTITY_IN_QUEUE),
DECODE(WO.QUANTITY_RUNNING, 0, NULL, WO.QUANTITY_RUNNING),
DECODE(WO.QUANTITY_WAITING_TO_MOVE,
0,
NULL,
WO.QUANTITY_WAITING_TO_MOVE),
DECODE(WO.QUANTITY_REJECTED, 0, NULL, WO.QUANTITY_REJECTED),
DECODE(WO.QUANTITY_SCRAPPED, 0, NULL, WO.QUANTITY_SCRAPPED),
DECODE(WO.QUANTITY_COMPLETED, 0, NULL, WO.QUANTITY_COMPLETED),
WO.FIRST_UNIT_START_DATE,
WO.FIRST_UNIT_COMPLETION_DATE,
WO.LAST_UNIT_START_DATE,
WO.LAST_UNIT_COMPLETION_DATE,
WO.PREVIOUS_OPERATION_SEQ_NUM,
WO.NEXT_OPERATION_SEQ_NUM,
WO.COUNT_POINT_TYPE,
DECODE(WO.COUNT_POINT_TYPE, 1, 1, 2) "COUNT_POINT_FLAG",
DECODE(WO.COUNT_POINT_TYPE, 3, 2, 1) "AUTOCHARGE_FLAG",
WO.BACKFLUSH_FLAG,
WO.MINIMUM_TRANSFER_QUANTITY,
WO.DATE_LAST_MOVED,
WO.ATTRIBUTE_CATEGORY,
WO.ATTRIBUTE1,
WO.ATTRIBUTE2,
WO.ATTRIBUTE3,
WO.ATTRIBUTE4,
WO.ATTRIBUTE5,
WO.ATTRIBUTE6,
WO.ATTRIBUTE7,
WO.ATTRIBUTE8,
WO.ATTRIBUTE9,
WO.ATTRIBUTE10,
WO.ATTRIBUTE11,
WO.ATTRIBUTE12,
WO.ATTRIBUTE13,
WO.ATTRIBUTE14,
WO.ATTRIBUTE15,
WO.OPERATION_YIELD,
WO.CUMULATIVE_SCRAP_QUANTITY,
WO.OPERATION_YIELD_ENABLED,
NVL(WO.OPERATION_COMPLETED, 'N'),
WO.SHUTDOWN_TYPE,
LU1.MEANING,
WO.X_POS,
WO.Y_POS,
WO.LONG_DESCRIPTION,
WO.DISABLE_DATE,
WO.RECOMMENDED,
WO.PROGRESS_PERCENTAGE,
WO.WSM_BONUS_QUANTITY,
WO.ACTUAL_START_DATE,
WO.ACTUAL_COMPLETION_DATE,
WO.EMPLOYEE_ID,
PAP.FULL_NAME,
WO.LOWEST_ACCEPTABLE_YIELD,
nvl(wo.CHECK_SKILL, 2) CHECK_SKILL
FROM BOM_DEPARTMENTS BD,
BOM_STANDARD_OPERATIONS BSO,
WIP_OPERATIONS WO,
MFG_LOOKUPS LU1,
PER_ALL_PEOPLE_F PAP
WHERE BD.DEPARTMENT_ID = WO.DEPARTMENT_ID
AND BSO.STANDARD_OPERATION_ID(+) = WO.STANDARD_OPERATION_ID
AND NVL(BSO.OPERATION_TYPE, 1) = 1
AND BSO.LINE_ID IS NULL
AND LU1.LOOKUP_TYPE(+) = 'BOM_EAM_SHUTDOWN_TYPE'
AND LU1.LOOKUP_CODE(+) = WO.SHUTDOWN_TYPE
AND WO.EMPLOYEE_ID = PAP.PERSON_ID(+)
ORDER BY WO.OPERATION_SEQ_NUM;
我靠视图里面有 ORDER BY ...... 这不是脑残吗？ 视图里面你搞ORDER BY 干嘛呢，直接在 视图外面写order by 呀。
select .... from a, v_b where a.id=b.id;
a 是一个表， v_b 是一个视图。 v_b 里面有order by 那么 v_b 是有序的， v_b 里面没order by 那么v_b 是无序的。
但是最终的 sql 返回结果 有没有顺序 是 在 最外面 搞 order by 对吧。
所以让 那哥们把视图里面的order by 给去掉 ，结果里面返回结果了。 执行计划就不 贴了，视图里面有 order by 会干扰执行计划的。
别在视图里面搞ORDER BY ，如果有需要 ，请在 外面sql 进行order by。
想要跟我学SQL优化的，请点击这里