我在这个查询中的逻辑是正确的（我80％确定它是）。但它已经运行了2小时23分钟仍在继续，我想知道是否有人可以帮助我提高运行效率，因为我不认为这是一个强烈的查询
SELECT b.bridge_no, COUNT(*) AS comment_cnt
FROM iacd_asset b INNER JOIN iacd_note c
ON REGEXP_LIKE(c.comments, '(^|\W)BN' || b.bridge_no || '(\W|$)', 'i')
inner join ncr_note e on c.note_id=e.note_id
inner join ncr f on e.ncr_id=f.ncr_id
inner join ncr_iac g on f.ncr_id=g.ncr_id
WHERE c.create_dt >= date'2015-01-01'
AND c.create_dt < date'2015-03-12'
AND length(b.bridge_no) > 1
AND g.scheme in (1, 3, 5, 6, 7, 8, 9, 9, and about 10 more values)
GROUP BY b.bridge_no
ORDER BY comment_cnt;
简而言之，查询应该是一堆连接，然后通过scheme（g.scheme in ....）过滤连接表，然后解析notes字段中包含BN的任何内容。
PLAN TABLE，好吧，我之前从未使用过，但我相信这是计划表
+------------------+----------------+--------------+------------------+--------------+-----------------+----------------+-----------+----+-----------+-------+----------+---------+-------------+-------------+-----------------+---------+------------+-----------------------------+---------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------+------+--------------+
| OPERATION | OPTIONS | OBJECT_OWNER | OBJECT_NAME | OBJECT_ALIAS | OBJECT_INSTANCE | OBJECT_TYPE | OPTIMIZER | ID | PARENT_ID | DEPTH | POSITION | COST | CARDINALITY | BYTES | CPU_COST | IO_COST | TEMP_SPACE | ACCESS_PREDICATES | FILTER_PREDICATES | PROJECTION | TIME | QBLOCK_NAME |
+------------------+----------------+--------------+------------------+--------------+-----------------+----------------+-----------+----+-----------+-------+----------+---------+-------------+-------------+-----------------+---------+------------+-----------------------------+---------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------+------+--------------+
| SELECT STATEMENT | | | | | | | ALL_ROWS | 0 | | 0 | 281,503 | 281,503 | 40 | 4,480 | 148,378,917,975 | 215,677 | | | | | 458 | |
+------------------+----------------+--------------+------------------+--------------+-----------------+----------------+-----------+----+-----------+-------+----------+---------+-------------+-------------+-----------------+---------+------------+-----------------------------+---------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------+------+--------------+
| SORT | ORDER BY | | | | | | | 1 | 0 | 1 | 1 | 281,503 | 40 | 4,480 | 148,378,917,975 | 215,677 | | | | (#keys=1) COUNT(*)[22], "B"."BRIDGE_NO"[NUMBER,22] | 458 | SEL$81719215 |
+------------------+----------------+--------------+------------------+--------------+-----------------+----------------+-----------+----+-----------+-------+----------+---------+-------------+-------------+-----------------+---------+------------+-----------------------------+---------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------+------+--------------+
| HASH | GROUP BY | | | | | | | 2 | 1 | 2 | 1 | 281,503 | 40 | 4,480 | 148,378,917,975 | 215,677 | | | | (#keys=1) "B"."BRIDGE_NO"[NUMBER,22], COUNT(*)[22] | 458 | |
+------------------+----------------+--------------+------------------+--------------+-----------------+----------------+-----------+----+-----------+-------+----------+---------+-------------+-------------+-----------------+---------+------------+-----------------------------+---------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------+------+--------------+
| HASH JOIN | | | | | | | | 3 | 2 | 3 | 1 | 281,497 | 16,084 | 1,801,408 | 148,366,537,976 | 215,677 | 24,126,000 | "G"."NCR_ID"="F"."NCR_ID" | | (#keys=1) "B"."BRIDGE_NO"[NUMBER,22] | 458 | |
+------------------+----------------+--------------+------------------+--------------+-----------------+----------------+-----------+----+-----------+-------+----------+---------+-------------+-------------+-----------------+---------+------------+-----------------------------+---------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------+------+--------------+
| HASH JOIN | | | | | | | | 4 | 3 | 4 | 1 | 96,996 | 209,778 | 21,607,134 | 13,549,630,814 | 90,985 | 22,725,000 | "E"."NCR_ID"="F"."NCR_ID" | | (#keys=1) "F"."NCR_ID"[NUMBER,22], "B"."BRIDGE_NO"[NUMBER,22] | 158 | |
+------------------+----------------+--------------+------------------+--------------+-----------------+----------------+-----------+----+-----------+-------+----------+---------+-------------+-------------+-----------------+---------+------------+-----------------------------+---------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------+------+--------------+
| HASH JOIN | | | | | | | | 5 | 4 | 5 | 1 | 42,595 | 208,419 | 20,216,643 | 5,484,063,163 | 40,162 | 9,839,000 | "C"."NOTE_ID"="E"."NOTE_ID" | REGEXP_LIKE ("C"."COMMENTS",'(^|\W)BN'||TO_CHAR("B"."BRIDGE_NO")||'(\W|$)','i') | (#keys=1) "B"."BRIDGE_NO"[NUMBER,22], "E"."NCR_ID"[NUMBER,22] | 70 | |
+------------------+----------------+--------------+------------------+--------------+-----------------+----------------+-----------+----+-----------+-------+----------+---------+-------------+-------------+-----------------+---------+------------+-----------------------------+---------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------+------+--------------+
| PARTITION RANGE | SINGLE | | | | | | | 6 | 5 | 6 | 1 | 1,039 | 104,603 | 8,577,446 | 62,280,224 | 1,011 | | | | "C"."NOTE_ID"[NUMBER,22], "C"."COMMENTS"[VARCHAR2,4000] | 2 | |
+------------------+----------------+--------------+------------------+--------------+-----------------+----------------+-----------+----+-----------+-------+----------+---------+-------------+-------------+-----------------+---------+------------+-----------------------------+---------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------+------+--------------+
| TABLE ACCESS | FULL | IACDB | IACD_NOTE | C@SEL$1 | 2 | TABLE | ANALYZED | 7 | 6 | 7 | 1 | 1,039 | 104,603 | 8,577,446 | 62,280,224 | 1,011 | | | "C"."CREATE_DATE"<TO_DATE(' 2014-12-31 00:00:00', 'syyyy-mm-dd hh24:mi:ss') | "C"."NOTE_ID"[NUMBER,22], "C"."COMMENTS"[VARCHAR2,4000] | 2 | SEL$81719215 |
+------------------+----------------+--------------+------------------+--------------+-----------------+----------------+-----------+----+-----------+-------+----------+---------+-------------+-------------+-----------------+---------+------------+-----------------------------+---------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------+------+--------------+
| MERGE JOIN | CARTESIAN | | | | | | | 8 | 5 | 6 | 2 | 24,267 | 12,268,270 | 184,024,050 | 2,780,501,758 | 23,033 | | | | (#keys=0) "B"."BRIDGE_NO"[NUMBER,22], "E"."NCR_ID"[NUMBER,22], "E"."NOTE_ID"[NUMBER,22] | 40 | |
+------------------+----------------+--------------+------------------+--------------+-----------------+----------------+-----------+----+-----------+-------+----------+---------+-------------+-------------+-----------------+---------+------------+-----------------------------+---------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------+------+--------------+
| TABLE ACCESS | FULL | IACDB | IACD_ASSET | B@SEL$1 | 1 | TABLE | ANALYZED | 9 | 8 | 7 | 1 | 7 | 40 | 160 | 560,542 | 7 | | | LENGTH(TO_CHAR("B"."BRIDGE_NO"))>1 | "B"."BRIDGE_NO"[NUMBER,22] | 1 | SEL$81719215 |
+------------------+----------------+--------------+------------------+--------------+-----------------+----------------+-----------+----+-----------+-------+----------+---------+-------------+-------------+-----------------+---------+------------+-----------------------------+---------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------+------+--------------+
| BUFFER | SORT | | | | | | | 10 | 8 | 7 | 2 | 24,259 | 308,248 | 3,390,728 | 2,779,941,216 | 23,026 | | | | (#keys=0) "E"."NCR_ID"[NUMBER,22], "E"."NOTE_ID"[NUMBER,22] | 40 | |
+------------------+----------------+--------------+------------------+--------------+-----------------+----------------+-----------+----+-----------+-------+----------+---------+-------------+-------------+-----------------+---------+------------+-----------------------------+---------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------+------+--------------+
| TABLE ACCESS | FULL | IACDB | IACD_NCR_NOTE | E@SEL$2 | 4 | TABLE | ANALYZED | 11 | 10 | 8 | 1 | 606 | 308,248 | 3,390,728 | 69,498,530 | 576 | | | | "E"."NCR_ID"[NUMBER,22], "E"."NOTE_ID"[NUMBER,22] | 1 | SEL$81719215 |
+------------------+----------------+--------------+------------------+--------------+-----------------+----------------+-----------+----+-----------+-------+----------+---------+-------------+-------------+-----------------+---------+------------+-----------------------------+---------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------+------+--------------+
| INDEX | FAST FULL SCAN | IACDB | PK_IACDNCR_NCRID | F@SEL$3 | | INDEX (UNIQUE) | ANALYZED | 12 | 4 | 5 | 2 | 31,763 | 22,838,996 | 137,033,976 | 3,248,120,913 | 30,322 | | | | "F"."NCR_ID"[NUMBER,22] | 52 | SEL$81719215 |
+------------------+----------------+--------------+------------------+--------------+-----------------+----------------+-----------+----+-----------+-------+----------+---------+-------------+-------------+-----------------+---------+------------+-----------------------------+---------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------+------+--------------+
| TABLE ACCESS | FULL | IACDB | IACD_NCR_IAC | G@SEL$4 | 8 | TABLE | ANALYZED | 13 | 3 | 4 | 2 | 181,461 | 1,731,062 | 15,579,558 | 134,407,812,606 | 121,833 | | | ALL THE SCHEMES CHCECKS | "G"."NCR_ID"[NUMBER,22] | 295 | SEL$81719215 |
+------------------+----------------+--------------+------------------+--------------+-----------------+----------------+-----------+----+-----------+-------+----------+---------+-------------+-------------+-----------------+---------+------------+-----------------------------+---------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------+------+--------------+
希望这足够清晰
索引的内容我假设只有被排序的字段是重要的 crate_dt未编入索引 scheme id已编入索引
也许我的查询顺序错了......
答案 0 :(得分：2)
计划显示你正在进行IACD_NOTE和IACD_ASSET的全表扫描，然后对它们进行CARETESIAN连接，因为你提供了无标准，用于将IACD_ASSET中的一条记录链接到一组IACD_NOTE中的记录。
这不是我对非强烈查询的定义，而且CPU成本的令人eye目结舌的值也证明了这一点。
您需要替换此..，
FROM iacd_asset b INNER JOIN iacd_note c
ON REGEXP_LIKE(c.comments, '(^|\W)BN' || b.bridge_no || '(\W|$)', 'i')
...在索引列上实际连接。如果Notes通过BRIDGE_NO或类似的外键链接到Assets会很有帮助。我不知道你的数据模型。然后，您可以将该正则表达式用作WHERE子句中的附加过滤器。
此外，您还要加入另外三个表，以获得允许在SCHEME上添加其他过滤器的内容。同样，我不知道你的数据模型，但这似乎效率很低。
不幸的是，这种依赖于领域知识的调整。修复此查询需要了解数据 - 数据量，分布和偏差，数据模型本身以及查询实现的业务逻辑。这超出了我们在StackOverflow中提供的建议的范围。
有一点需要考虑，但是一个重要的决定是用自由文本索引索引注释。但是，这有很多分支（特别是空间和数据库管理员）。 Find out more