我想根据以下查询创建一个视图：
create or replace view MY_VIEW as
select A.*
from MY_TABLE A, table(MY_PACKAGE.PIPELINED_FUNCTION(A.MY_DATE)) P
where A.MY_FIELD1 = P.MY_FIELD1
and ...
视图应该以这种方式使用：
select *
from MY_VIEW V
where V.MY_DATE = trunc(sysdate)
正如您所看到的，我的请求有点棘手，因为使用PIPELINED_FUNCTION中的字段调用了A！我的请求非常慢，我怀疑是因为Oracle尝试使用所有可能的日期来计算P。当然，如果我修正日期（例如MY_PACKAGE.PIPELINED_FUNCTION(trunc(sysdate))），答案是立即的。
以下是执行计划（MY_TABLE实际上是一个视图：FO.V_TRADING_POOL_INOUT_PRD，流水线名称实际上是POOL_INOUT_ELIG_BEST_RANK在底部）：
SELECT STATEMENT, GOAL = ALL_ROWS 211 2 16576 191
VIEW FO V_TRADING_POOL_INOUT_CANDIDATE 211 2 16576 191
NESTED LOOPS 130 1 8290 115
VIEW FO V_TRADING_POOL_INOUT_PRD 63 1 8288 56
SORT GROUP BY 63 1 941 56
NESTED LOOPS OUTER 62 1 941 56
NESTED LOOPS OUTER 61 1 928 55
NESTED LOOPS 60 1 894 54
NESTED LOOPS 59 1 884 53
NESTED LOOPS 58 1 874 52
NESTED LOOPS OUTER 57 1 832 51
NESTED LOOPS OUTER 56 1 794 50
NESTED LOOPS OUTER 55 1 757 49
NESTED LOOPS OUTER 54 1 720 48
NESTED LOOPS OUTER 53 1 683 47
NESTED LOOPS OUTER 52 1 670 46
HASH JOIN 51 1 657 45
INDEX FULL SCAN FO TRADING_POOL_GROUP_PK 1 113 678 1
HASH JOIN RIGHT OUTER 49 18 11718 44
VIEW FO 16 63 4221 13
HASH JOIN 16 63 4536 13
HASH JOIN OUTER 13 63 3843 11
FILTER
HASH JOIN OUTER 9 63 3276 8
HASH JOIN 3 81 2025 2
INDEX FULL SCAN FO TRADING_POOL_GROUP_PK 1 113 678 1
INDEX RANGE SCAN FO TRADING_POOL_IO_EQT_IDX1 1 157 2983 1
TABLE ACCESS BY INDEX ROWID FO PRODUCT_BLACKLIST 6 33 891 6
INDEX RANGE SCAN FO PRODUCT_BLACKLIST_IDX2 2 33 2
TABLE ACCESS FULL FO TRADING_POOL_GROUP_TRANS 3 6 54 3
VIEW FO index$_join$_024 3 96 1056 2
HASH JOIN
INDEX FAST FULL SCAN FO SYS_C0018504 1 96 1056 1
INDEX FAST FULL SCAN FO TRADING_POOL_DEF_PK 1 96 1056 1
NESTED LOOPS OUTER 33 18 10512 31
NESTED LOOPS OUTER 30 18 9882 29
FILTER
HASH JOIN RIGHT OUTER 29 18 9666 28
TABLE ACCESS BY INDEX ROWID FO PRODUCT_VALIDATION 1 13 988 1
INDEX RANGE SCAN FO PRODUCT_VALIDATION_IDX1 1 13 1
NESTED LOOPS
NESTED LOOPS 28 18 8298 26
NESTED LOOPS 25 18 7956 24
TABLE ACCESS BY INDEX ROWID FO TRADING_POOL_CONTEXT 1 1 9 1
INDEX UNIQUE SCAN FO TRADING_POOL_CTXT_PK 1 1 1
VIEW FO 24 18 7794 23
SORT GROUP BY 24 18 4950 23
NESTED LOOPS OUTER 23 18 4950 23
TABLE ACCESS BY INDEX ROWID FO TRADING_POOL_INOUT_PRD 18 18 3510 18
INDEX RANGE SCAN FO TRADING_POOL_IO_EQT_IDX1 1 157 1
TABLE ACCESS BY INDEX ROWID FO PRODUCT_BLACKLIST 1 1 80 1
INDEX RANGE SCAN FO PRODUCT_BLACKLIST_IDX2 1 1 1
INDEX UNIQUE SCAN FO TRADING_POOL_PROCESS_TYPE_PK 1 1 1
TABLE ACCESS BY INDEX ROWID FO TRADING_POOL_PROCESS_TYPE 1 1 19 1
TABLE ACCESS BY INDEX ROWID FO TRADING_POOL_RULE_DEF 1 1 12 1
INDEX UNIQUE SCAN FO TRADING_POOL_RULE_DEF_PK 1 1 1
TABLE ACCESS BY INDEX ROWID FO TRADING_POOL 1 1 35 1
INDEX RANGE SCAN FO TRADING_POOL_IDX3 1 1 1
TABLE ACCESS BY INDEX ROWID CFMLOG INTRANET_USERS 1 1 13 1
INDEX UNIQUE SCAN CFMLOG PK_INTRANET_USERS 1 1 1
TABLE ACCESS BY INDEX ROWID CFMLOG INTRANET_USERS 1 1 13 1
INDEX UNIQUE SCAN CFMLOG PK_INTRANET_USERS 1 1 1
TABLE ACCESS BY INDEX ROWID DATA PRODUCT_DICTIONARY 1 1 37 1
INDEX RANGE SCAN DATA PRODUCT_DICTIONARY_PK 1 1 1
TABLE ACCESS BY INDEX ROWID DATA PRODUCT_DICTIONARY 1 1 37 1
INDEX RANGE SCAN DATA PRODUCT_DICTIONARY_PK 1 1 1
TABLE ACCESS BY INDEX ROWID DATA PRODUCT_DICTIONARY 1 1 37 1
INDEX RANGE SCAN DATA PRODUCT_DICTIONARY_PK 1 1 1
TABLE ACCESS BY INDEX ROWID DATA MARKETS 1 1 38 1
INDEX UNIQUE SCAN DATA MARKETS_MKT_ID_PK 1 1 1
TABLE ACCESS BY INDEX ROWID FO TRADING_POOL_DEF 1 1 42 1
INDEX UNIQUE SCAN FO TRADING_POOL_DEF_PK 1 1 1
TABLE ACCESS BY INDEX ROWID FO STRATEGY 1 1 10 1
INDEX UNIQUE SCAN FO STRAT_PK 1 1 1
TABLE ACCESS BY INDEX ROWID DATA CURRENCY 1 1 10 1
INDEX UNIQUE SCAN DATA CURRENCY_PK 1 1 1
TABLE ACCESS BY INDEX ROWID DATA REFERENTIAL_DICTIONARY 1 1 34 1
INDEX RANGE SCAN DATA REFERENTIAL_DICTIONARY_PK 1 1 1
TABLE ACCESS BY INDEX ROWID CFMLOG INTRANET_USERS 1 1 13 1
INDEX UNIQUE SCAN CFMLOG PK_INTRANET_USERS 1 1 1
COLLECTION ITERATOR PICKLER FETCH POOL_RULE_COMMON POOL_INOUT_ELIG_BEST_RANK 67 1 2 59
使用的真实查询：
select *
from fo.v_trading_pool_inout_candidate c
where c.POOL_DATE = trunc(sysdate)
and c.STRATEGY_ID = 2;
有没有办法（重构？提示？）来改善我的观点的表现？ 非常感谢！
答案 0 :(得分：1)
我的第一个想法是： 你还没有展示所有的联接，所以我们无法真正看到你为何有这个糟糕计划的所有原因。似乎有外连接 - 可能在我们不知道的功能中....
将隐式连接更改为显式内连接。不推荐使用where子句加入。
流水线功能本身可能不是最快的答案。我怀疑虽然不需要看到它里面有什么。
答案 1 :(得分：1)
我最终重写了一个新的流水线函数，它将表的查询和旧的流水线函数分组;我找不到任何暗示Oracle将查询限制在给定日期的提示。