前言
在表擴展中，對于讀取一個分區表部分數據時優化器會生成使用索引的執行計劃。基于索引執行計劃可以提高性能，但索引維護會增加開鎖。在許多數據庫中，DML只影響小部分數據。對于頻繁更新的表表擴展使用基于索引的執行計劃。你可以在以讀取為主的數據上創建一個索引，在以頻繁變化的數據上消除索引開銷。通過這種方式，表擴展在避免索引維護的同時提高了性能。
下面話不多說了，來一起看看詳細的介紹吧
表擴展工作原理
表分區使用表擴展成為可能。如果在一個分區表上創建一個本地索引，那么優化器可能會標記索引對于特定的分區不可使用。實際有些分區沒有創建索引。在表擴展中，優化器將查詢轉換為一個union all語句，讓一些子查詢訪問創建索引的分區，一些子查詢訪問沒有創建索引的分區。優化器可以為每個分區選擇最有效的訪問路徑，而不管它是否存在于查詢所要訪問的所有分區中。
優化器不總是會選擇表擴展
.表擴展是基于成本
當數據庫訪問擴展表的每個分區只會跨越union all的所有分支一次，數據庫所連接的任何表都是在分支中被訪問。
.語義問題可能導致表擴展無效
例如，一個表出現在一個外連接的右邊對于表擴展來說是無效的。
可以使用expand_table hint來控制表擴展。這個hint會覆蓋基于成本的決策，但不會覆蓋語義檢查。
表擴展使用場景
優化器基于查詢中出現的謂詞條件對每個表必須被訪問的分區保持跟蹤。分區裁剪能讓優化器使用表擴展來生成更有效的執行計劃。
下面的例子假設滿足以下條件:
.想要對sh.sales表執行星型查詢，表sh.sales是基于time_id列進行范圍分區的一個分區表。
.想要禁用特定分區上的索引來查看表擴展的優點。
操作步驟如下:
1.以sh用戶登錄數據庫
[oracle@jytest1 ~]$ sqlplus sh/*****@jypdbSQL*Plus: Release 12.2.0.1.0 Production on Wed Oct 31 18:09:54 2018Copyright (c) 1982, 2016, Oracle. All rights reserved.Last Successful login time: Wed Oct 24 2018 17:00:11 +08:00Connected to:Oracle Database 12c Enterprise Edition Release 12.2.0.1.0 - 64bit ProductionSQL>
2.執行以下查詢
SQL> select * from sales where time_id >= to_date('2000-01-01 00:00:00', 'syyyy-mm-dd hh24:mi:ss') and prod_id = 38;........... 38 2470 24-DEC-01 2 999 1 31.47 38 13440 24-DEC-01 2 999 1 31.47 38 490 28-DEC-01 2 999 1 31.47 38 8406 28-DEC-01 2 999 1 31.47 38 1466 31-DEC-01 3 351 1 31.47 38 4340 31-DEC-01 3 351 1 31.47 38 10658 31-DEC-01 3 351 1 31.47 38 11390 31-DEC-01 3 351 1 31.47 38 23226 31-DEC-01 3 351 1 31.474224 rows selected.3.查詢執行計劃
SQL> select * from table(dbms_xplan.display_cursor(null,null,'advanced allstats last runstats_last peeked_binds'));SQL_ID 214qgysqqz0k8, child number 0-------------------------------------select * from sales where time_id >= to_date('2000-01-01 00:00:00','syyyy-mm-dd hh24:mi:ss') and prod_id = 38Plan hash value: 2342444420-----------------------------------------------------------------------------------------------------------------------------------------------------------------------| Id | Operation | Name | Starts | E-Rows |E-Bytes| Cost (%CPU)| E-Time | Pstart| Pstop | A-Rows | A-Time | Buffers |-----------------------------------------------------------------------------------------------------------------------------------------------------------------------| 0 | SELECT STATEMENT | | 1 | | | 224 (100)| | | | 4224 |00:00:00.03 | 334 || 1 | PARTITION RANGE ITERATOR | | 1 | 5078 | 143K| 224 (0)| 00:00:01 | 13 | 28 | 4224 |00:00:00.03 | 334 || 2 | TABLE ACCESS BY LOCAL INDEX ROWID BATCHED| SALES | 16 | 5078 | 143K| 224 (0)| 00:00:01 | 13 | 28 | 4224 |00:00:00.02 | 334 || 3 | BITMAP CONVERSION TO ROWIDS | | 8 | | | | | | | 4224 |00:00:00.01 | 24 ||* 4 | BITMAP INDEX SINGLE VALUE | SALES_PROD_BIX | 8 | | | | | 13 | 28 | 8 |00:00:00.01 | 24 |-----------------------------------------------------------------------------------------------------------------------------------------------------------------------Query Block Name / Object Alias (identified by operation id):------------------------------------------------------------- 1 - SEL$1 2 - SEL$1 / SALES@SEL$1Outline Data------------- /*+ BEGIN_OUTLINE_DATA IGNORE_OPTIM_EMBEDDED_HINTS OPTIMIZER_FEATURES_ENABLE('12.2.0.1') DB_VERSION('12.2.0.1') ALL_ROWS NO_PARALLEL OUTLINE_LEAF(@"SEL$1") BITMAP_TREE(@"SEL$1" "SALES"@"SEL$1" AND(("SALES"."PROD_ID"))) BATCH_TABLE_ACCESS_BY_ROWID(@"SEL$1" "SALES"@"SEL$1") END_OUTLINE_DATA */Predicate Information (identified by operation id):--------------------------------------------------- 4 - access("PROD_ID"=38)Column Projection Information (identified by operation id):----------------------------------------------------------- 1 - "PROD_ID"[NUMBER,22], "SALES"."CUST_ID"[NUMBER,22], "SALES"."TIME_ID"[DATE,7], "SALES"."CHANNEL_ID"[NUMBER,22], "SALES"."PROMO_ID"[NUMBER,22], "SALES"."QUANTITY_SOLD"[NUMBER,22], "SALES"."AMOUNT_SOLD"[NUMBER,22] 2 - "PROD_ID"[NUMBER,22], "SALES"."CUST_ID"[NUMBER,22], "SALES"."TIME_ID"[DATE,7], "SALES"."CHANNEL_ID"[NUMBER,22], "SALES"."PROMO_ID"[NUMBER,22], "SALES"."QUANTITY_SOLD"[NUMBER,22], "SALES"."AMOUNT_SOLD"[NUMBER,22] 3 - "SALES".ROWID[ROWID,10], "PROD_ID"[NUMBER,22] 4 - STRDEF[BM VAR, 10], STRDEF[BM VAR, 10], STRDEF[BM VAR, 7920], "PROD_ID"[NUMBER,22]Note----- - automatic DOP: Computed Degree of Parallelism is 1 because of parallel threshold58 rows selected.在執行計劃中的Pstart與Pstop列，顯示了優化器判斷只需要訪問表的13到28分區。在優化器已經判斷了被訪問的分區之后，它將考慮所有這些分區上可以使用的索引。在上面的執行計劃中，優化器選擇使用sales_prod_bix位圖索引
4.禁用sales表中sales_1995分區上的索引;
SQL> alter index sales_prod_bix modify partition sales_1995 unusable;Index altered.
5.再次執行之前的查詢語句，然后顯示執行計劃，可以看到執行計劃變成了由兩個子查詢組成的union all語句，第一個子查詢還是對13-28分區使用索引，第二個子查詢步驟對應的Pstart與Pstop為invalid，id=11的過濾條件為”PROD_ID”=38,id=9的過濾條件為”SALES”.”TIME_ID”=TO_DATE(‘ 2000-01-01 00:00:00', ‘syyyy-mm-dd hh24:mi:ss')))這個過濾條件是為否的，所以過濾后的記錄為0，從對應的A-Rows列也可以看到記錄為0
SQL> select * from table(dbms_xplan.display_cursor(null,null,'advanced allstats last runstats_last peeked_binds'));SQL_ID 214qgysqqz0k8, child number 0-------------------------------------select * from sales where time_id >= to_date('2000-01-01 00:00:00','syyyy-mm-dd hh24:mi:ss') and prod_id = 38Plan hash value: 238952339--------------------------------------------------------------------------------------------------------------------------------------------------------------------------| Id | Operation | Name | Starts | E-Rows |E-Bytes| Cost (%CPU)| E-Time | Pstart| Pstop | A-Rows | A-Time | Buffers |--------------------------------------------------------------------------------------------------------------------------------------------------------------------------| 0 | SELECT STATEMENT | | 1 | | | 224 (100)| | | | 4224 |00:00:00.05 | 334 || 1 | VIEW | VW_TE_2 | 1 | 5079 | 431K| 224 (0)| 00:00:01 | | | 4224 |00:00:00.05 | 334 || 2 | UNION-ALL | | 1 | | | | | | | 4224 |00:00:00.05 | 334 || 3 | PARTITION RANGE ITERATOR | | 1 | 5078 | 143K| 224 (0)| 00:00:01 | 13 | 28 | 4224 |00:00:00.03 | 334 || 4 | TABLE ACCESS BY LOCAL INDEX ROWID BATCHED | SALES | 16 | 5078 | 143K| 224 (0)| 00:00:01 | 13 | 28 | 4224 |00:00:00.02 | 334 || 5 | BITMAP CONVERSION TO ROWIDS | | 8 | | | | | | | 4224 |00:00:00.01 | 24 ||* 6 | BITMAP INDEX SINGLE VALUE | SALES_PROD_BIX | 8 | | | | | 13 | 28 | 8 |00:00:00.01 | 24 ||* 7 | FILTER | | 1 | | | | | | | 0 |00:00:00.01 | 0 || 8 | PARTITION RANGE EMPTY | | 0 | 1 | 29 | 1 (0)| 00:00:01 |INVALID|INVALID| 0 |00:00:00.01 | 0 ||* 9 | TABLE ACCESS BY LOCAL INDEX ROWID BATCHED| SALES | 0 | 1 | 29 | 1 (0)| 00:00:01 |INVALID|INVALID| 0 |00:00:00.01 | 0 || 10 | BITMAP CONVERSION TO ROWIDS | | 0 | | | | | | | 0 |00:00:00.01 | 0 ||* 11 | BITMAP INDEX SINGLE VALUE | SALES_PROD_BIX | 0 | | | | |INVALID|INVALID| 0 |00:00:00.01 | 0 |--------------------------------------------------------------------------------------------------------------------------------------------------------------------------Query Block Name / Object Alias (identified by operation id):------------------------------------------------------------- 1 - SET$D0A14387 / VW_TE_2@SEL$0A5B0FFE 2 - SET$D0A14387 3 - SET$D0A14387_1 4 - SET$D0A14387_1 / SALES@SEL$1 7 - SET$D0A14387_2 9 - SET$D0A14387_2 / SALES@SEL$1Outline Data------------- /*+ BEGIN_OUTLINE_DATA IGNORE_OPTIM_EMBEDDED_HINTS OPTIMIZER_FEATURES_ENABLE('12.2.0.1') DB_VERSION('12.2.0.1') ALL_ROWS NO_PARALLEL OUTLINE_LEAF(@"SET$D0A14387_2") OUTLINE_LEAF(@"SET$D0A14387_1") OUTLINE_LEAF(@"SET$D0A14387") EXPAND_TABLE(@"SEL$1" "SALES"@"SEL$1") OUTLINE_LEAF(@"SEL$0A5B0FFE") OUTLINE(@"SET$D0A14387") EXPAND_TABLE(@"SEL$1" "SALES"@"SEL$1") OUTLINE(@"SEL$1") NO_ACCESS(@"SEL$0A5B0FFE" "VW_TE_2"@"SEL$0A5B0FFE") BITMAP_TREE(@"SET$D0A14387_1" "SALES"@"SEL$1" AND(("SALES"."PROD_ID"))) BATCH_TABLE_ACCESS_BY_ROWID(@"SET$D0A14387_1" "SALES"@"SEL$1") BITMAP_TREE(@"SET$D0A14387_2" "SALES"@"SEL$1" AND(("SALES"."PROD_ID"))) BATCH_TABLE_ACCESS_BY_ROWID(@"SET$D0A14387_2" "SALES"@"SEL$1") END_OUTLINE_DATA */Predicate Information (identified by operation id):--------------------------------------------------- 6 - access("PROD_ID"=38) 7 - filter(NULL IS NOT NULL) 9 - filter(("SALES"."TIME_ID"=TO_DATE(' 2000-01-01 00:00:00', 'syyyy-mm-dd hh24:mi:ss'))) 11 - access("PROD_ID"=38)Column Projection Information (identified by operation id):----------------------------------------------------------- 1 - "ITEM_1"[NUMBER,22], "ITEM_2"[NUMBER,22], "ITEM_3"[DATE,7], "ITEM_4"[NUMBER,22], "ITEM_5"[NUMBER,22], "ITEM_6"[NUMBER,22], "ITEM_7"[NUMBER,22] 2 - STRDEF[22], STRDEF[22], STRDEF[7], STRDEF[22], STRDEF[22], STRDEF[22], STRDEF[22] 3 - "SALES"."PROD_ID"[NUMBER,22], "SALES"."CUST_ID"[NUMBER,22], "SALES"."TIME_ID"[DATE,7], "SALES"."CHANNEL_ID"[NUMBER,22], "SALES"."PROMO_ID"[NUMBER,22], "SALES"."QUANTITY_SOLD"[NUMBER,22], "SALES"."AMOUNT_SOLD"[NUMBER,22] 4 - "SALES"."PROD_ID"[NUMBER,22], "SALES"."CUST_ID"[NUMBER,22], "SALES"."TIME_ID"[DATE,7], "SALES"."CHANNEL_ID"[NUMBER,22], "SALES"."PROMO_ID"[NUMBER,22], "SALES"."QUANTITY_SOLD"[NUMBER,22], "SALES"."AMOUNT_SOLD"[NUMBER,22] 5 - "SALES".ROWID[ROWID,10], "SALES"."PROD_ID"[NUMBER,22] 6 - STRDEF[BM VAR, 10], STRDEF[BM VAR, 10], STRDEF[BM VAR, 7920], "SALES"."PROD_ID"[NUMBER,22] 7 - "SALES"."PROD_ID"[NUMBER,22], "SALES"."CUST_ID"[NUMBER,22], "SALES"."TIME_ID"[DATE,7], "SALES"."CHANNEL_ID"[NUMBER,22], "SALES"."PROMO_ID"[NUMBER,22], "SALES"."QUANTITY_SOLD"[NUMBER,22], "SALES"."AMOUNT_SOLD"[NUMBER,22] 8 - "SALES"."PROD_ID"[NUMBER,22], "SALES"."CUST_ID"[NUMBER,22], "SALES"."TIME_ID"[DATE,7], "SALES"."CHANNEL_ID"[NUMBER,22], "SALES"."PROMO_ID"[NUMBER,22], "SALES"."QUANTITY_SOLD"[NUMBER,22], "SALES"."AMOUNT_SOLD"[NUMBER,22] 9 - "SALES"."PROD_ID"[NUMBER,22], "SALES"."CUST_ID"[NUMBER,22], "SALES"."TIME_ID"[DATE,7], "SALES"."CHANNEL_ID"[NUMBER,22], "SALES"."PROMO_ID"[NUMBER,22], "SALES"."QUANTITY_SOLD"[NUMBER,22], "SALES"."AMOUNT_SOLD"[NUMBER,22] 10 - "SALES".ROWID[ROWID,10], "SALES"."PROD_ID"[NUMBER,22] 11 - STRDEF[BM VAR, 10], STRDEF[BM VAR, 10], STRDEF[BM VAR, 7920], "SALES"."PROD_ID"[NUMBER,22]Note----- - automatic DOP: Computed Degree of Parallelism is 1 because of parallel threshold93 rows selected.6.禁用分區28上的索引(sales_q4_2003),它是查詢需要訪問的一個分區:
SQL> alter index sales_prod_bix modify partition sales_q4_2003 unusable;Index altered.SQL> alter index sales_time_bix modify partition sales_q4_2003 unusable;Index altered.
通過禁用查詢需要訪問分區上的索引，查詢將不能再使用這些索引。
7.再次執行查詢語句，其執行計劃如下,執行計劃變成了由三個子查詢組成的union all語句，相比之前查詢多的第三個子查詢對表sales的第28個分區執行全表掃描，這里沒有索引可用，因為已經禁用28分區上的索引了。
SQL> select * from table(dbms_xplan.display_cursor(null,null,'advanced allstats last runstats_last peeked_binds'));SQL_ID 214qgysqqz0k8, child number 0-------------------------------------select * from sales where time_id >= to_date('2000-01-01 00:00:00','syyyy-mm-dd hh24:mi:ss') and prod_id = 38Plan hash value: 3857158179-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| Id | Operation | Name | Starts | E-Rows |E-Bytes| Cost (%CPU)| E-Time | Pstart| Pstop | A-Rows | A-Time | Buffers | Reads |-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| 0 | SELECT STATEMENT | | 1 | | | 225 (100)| | | | 4224 |00:00:00.20 | 334 | 44 || 1 | VIEW | VW_TE_2 | 1 | 5080 | 431K| 225 (0)| 00:00:01 | | | 4224 |00:00:00.20 | 334 | 44 || 2 | UNION-ALL | | 1 | | | | | | | 4224 |00:00:00.19 | 334 | 44 || 3 | PARTITION RANGE ITERATOR | | 1 | 5078 | 143K| 223 (0)| 00:00:01 | 13 | 27 | 4224 |00:00:00.17 | 334 | 44 || 4 | TABLE ACCESS BY LOCAL INDEX ROWID BATCHED | SALES | 15 | 5078 | 143K| 223 (0)| 00:00:01 | 13 | 27 | 4224 |00:00:00.16 | 334 | 44 || 5 | BITMAP CONVERSION TO ROWIDS | | 8 | | | | | | | 4224 |00:00:00.03 | 24 | 16 ||* 6 | BITMAP INDEX SINGLE VALUE | SALES_PROD_BIX | 8 | | | | | 13 | 27 | 8 |00:00:00.03 | 24 | 16 ||* 7 | FILTER | | 1 | | | | | | | 0 |00:00:00.01 | 0 | 0 || 8 | PARTITION RANGE EMPTY | | 0 | 1 | 29 | 1 (0)| 00:00:01 |INVALID|INVALID| 0 |00:00:00.01 | 0 | 0 ||* 9 | TABLE ACCESS BY LOCAL INDEX ROWID BATCHED| SALES | 0 | 1 | 29 | 1 (0)| 00:00:01 |INVALID|INVALID| 0 |00:00:00.01 | 0 | 0 || 10 | BITMAP CONVERSION TO ROWIDS | | 0 | | | | | | | 0 |00:00:00.01 | 0 | 0 ||* 11 | BITMAP INDEX SINGLE VALUE | SALES_PROD_BIX | 0 | | | | |INVALID|INVALID| 0 |00:00:00.01 | 0 | 0 || 12 | PARTITION RANGE SINGLE | | 1 | 1 | 87 | 2 (0)| 00:00:01 | 28 | 28 | 0 |00:00:00.01 | 0 | 0 ||* 13 | TABLE ACCESS FULL | SALES | 1 | 1 | 87 | 2 (0)| 00:00:01 | 28 | 28 | 0 |00:00:00.01 | 0 | 0 |-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------Query Block Name / Object Alias (identified by operation id):------------------------------------------------------------- 1 - SET$D0A14387 / VW_TE_2@SEL$0A5B0FFE 2 - SET$D0A14387 3 - SET$D0A14387_1 4 - SET$D0A14387_1 / SALES@SEL$1 7 - SET$D0A14387_2 9 - SET$D0A14387_2 / SALES@SEL$1 12 - SET$D0A14387_3 13 - SET$D0A14387_3 / SALES@SEL$1Outline Data------------- /*+ BEGIN_OUTLINE_DATA IGNORE_OPTIM_EMBEDDED_HINTS OPTIMIZER_FEATURES_ENABLE('12.2.0.1') DB_VERSION('12.2.0.1') ALL_ROWS NO_PARALLEL OUTLINE_LEAF(@"SET$D0A14387_3") OUTLINE_LEAF(@"SET$D0A14387_2") OUTLINE_LEAF(@"SET$D0A14387_1") OUTLINE_LEAF(@"SET$D0A14387") EXPAND_TABLE(@"SEL$1" "SALES"@"SEL$1") OUTLINE_LEAF(@"SEL$0A5B0FFE") OUTLINE(@"SET$D0A14387") EXPAND_TABLE(@"SEL$1" "SALES"@"SEL$1") OUTLINE(@"SEL$1") NO_ACCESS(@"SEL$0A5B0FFE" "VW_TE_2"@"SEL$0A5B0FFE") BITMAP_TREE(@"SET$D0A14387_1" "SALES"@"SEL$1" AND(("SALES"."PROD_ID"))) BATCH_TABLE_ACCESS_BY_ROWID(@"SET$D0A14387_1" "SALES"@"SEL$1") BITMAP_TREE(@"SET$D0A14387_2" "SALES"@"SEL$1" AND(("SALES"."PROD_ID"))) BATCH_TABLE_ACCESS_BY_ROWID(@"SET$D0A14387_2" "SALES"@"SEL$1") FULL(@"SET$D0A14387_3" "SALES"@"SEL$1") END_OUTLINE_DATA */Predicate Information (identified by operation id):--------------------------------------------------- 6 - access("PROD_ID"=38) 7 - filter(NULL IS NOT NULL) 9 - filter(("SALES"."TIME_ID"=TO_DATE(' 2000-01-01 00:00:00', 'syyyy-mm-dd hh24:mi:ss'))) 11 - access("PROD_ID"=38) 13 - filter("PROD_ID"=38)Column Projection Information (identified by operation id):----------------------------------------------------------- 1 - "ITEM_1"[NUMBER,22], "ITEM_2"[NUMBER,22], "ITEM_3"[DATE,7], "ITEM_4"[NUMBER,22], "ITEM_5"[NUMBER,22], "ITEM_6"[NUMBER,22], "ITEM_7"[NUMBER,22] 2 - STRDEF[22], STRDEF[22], STRDEF[7], STRDEF[22], STRDEF[22], STRDEF[22], STRDEF[22] 3 - "SALES"."PROD_ID"[NUMBER,22], "SALES"."CUST_ID"[NUMBER,22], "SALES"."TIME_ID"[DATE,7], "SALES"."CHANNEL_ID"[NUMBER,22], "SALES"."PROMO_ID"[NUMBER,22], "SALES"."QUANTITY_SOLD"[NUMBER,22], "SALES"."AMOUNT_SOLD"[NUMBER,22] 4 - "SALES"."PROD_ID"[NUMBER,22], "SALES"."CUST_ID"[NUMBER,22], "SALES"."TIME_ID"[DATE,7], "SALES"."CHANNEL_ID"[NUMBER,22], "SALES"."PROMO_ID"[NUMBER,22], "SALES"."QUANTITY_SOLD"[NUMBER,22], "SALES"."AMOUNT_SOLD"[NUMBER,22] 5 - "SALES".ROWID[ROWID,10], "SALES"."PROD_ID"[NUMBER,22] 6 - STRDEF[BM VAR, 10], STRDEF[BM VAR, 10], STRDEF[BM VAR, 7920], "SALES"."PROD_ID"[NUMBER,22] 7 - "SALES"."PROD_ID"[NUMBER,22], "SALES"."CUST_ID"[NUMBER,22], "SALES"."TIME_ID"[DATE,7], "SALES"."CHANNEL_ID"[NUMBER,22], "SALES"."PROMO_ID"[NUMBER,22], "SALES"."QUANTITY_SOLD"[NUMBER,22], "SALES"."AMOUNT_SOLD"[NUMBER,22] 8 - "SALES"."PROD_ID"[NUMBER,22], "SALES"."CUST_ID"[NUMBER,22], "SALES"."TIME_ID"[DATE,7], "SALES"."CHANNEL_ID"[NUMBER,22], "SALES"."PROMO_ID"[NUMBER,22], "SALES"."QUANTITY_SOLD"[NUMBER,22], "SALES"."AMOUNT_SOLD"[NUMBER,22] 9 - "SALES"."PROD_ID"[NUMBER,22], "SALES"."CUST_ID"[NUMBER,22], "SALES"."TIME_ID"[DATE,7], "SALES"."CHANNEL_ID"[NUMBER,22], "SALES"."PROMO_ID"[NUMBER,22], "SALES"."QUANTITY_SOLD"[NUMBER,22], "SALES"."AMOUNT_SOLD"[NUMBER,22] 10 - "SALES".ROWID[ROWID,10], "SALES"."PROD_ID"[NUMBER,22] 11 - STRDEF[BM VAR, 10], STRDEF[BM VAR, 10], STRDEF[BM VAR, 7920], "SALES"."PROD_ID"[NUMBER,22] 12 - "SALES"."PROD_ID"[NUMBER,22], "SALES"."CUST_ID"[NUMBER,22], "SALES"."TIME_ID"[DATE,7], "SALES"."CHANNEL_ID"[NUMBER,22], "SALES"."PROMO_ID"[NUMBER,22], "SALES"."QUANTITY_SOLD"[NUMBER,22], "SALES"."AMOUNT_SOLD"[NUMBER,22] 13 - "SALES"."PROD_ID"[NUMBER,22], "SALES"."CUST_ID"[NUMBER,22], "SALES"."TIME_ID"[DATE,7], "SALES"."CHANNEL_ID"[NUMBER,22], "SALES"."PROMO_ID"[NUMBER,22], "SALES"."QUANTITY_SOLD"[NUMBER,22], "SALES"."AMOUNT_SOLD"[NUMBER,22]Note----- - automatic DOP: Computed Degree of Parallelism is 1 because of parallel threshold103 rows selected.總結
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