SQL 查询时间过长

Question

下面的查询需要很长时间，我正在尝试调整查询但它似乎不起作用。无论如何我可以重写查询吗？请帮助我调整查询。

 SELECT DISTINCT TC.V_ID,A.ID,A.NAME 
    FROM OM_A_DATA TC 
       INNER JOIN ACC_DOM_EXT AE ON TC.DOMAINS = AE.DOMAIN
        LEFT OUTER JOIN ACCOUNT A ON A.ID=AE.ACCOUNTID
    WHERE V_ID not in (select distinct V_ID from DATA_ACC_MAP)


OM_A_DATA  has 41,696,776 rows
ACC_DOM_EXT has 106,725 rows
ACCOUNT has 106731 rows
DATA_ACC_MAP has 91021 rows

Answer 1

通常 not exists 比 not in 效果更好：

SELECT DISTINCT TC.V_ID, A.ID, A.NAME 
FROM OM_A_DATA TC INNER JOIN
     ACC_DOM_EXT AE
     ON TC.DOMAINS = AE.DOMAIN LEFT OUTER JOIN
     ACCOUNT A
     ON A.ID = AE.ACCOUNTID
WHERE NOT EXISTS (SELECT 1 FROM DATA_ACC_MAP dam WHERE dam.V_ID = tc.V_ID );

显然，您应该在 DATA_ACC_MAP(V_ID) 上有一个索引。您还应该在其他列上有索引：OM_A_DATA(V_ID, DOMAINS)、ACC_DOM_EXT(DOMAIN, ACCOUNTID) 和 ACCOUNT(ID, NAME).

Answer 2

要么删除 DISTINCT。

SELECT DISTINCT TC.V_ID, A.ID, A.NAME 
FROM OM_A_DATA TC 
INNER JOIN ACC_DOM_EXT AE ON TC.DOMAINS = AE.DOMAIN
LEFT OUTER JOIN ACCOUNT A ON A.ID = AE.ACCOUNTID
WHERE V_ID NOT IN (SELECT V_ID FROM DATA_ACC_MAP)

或者使用 INNER JOIN 而不是子查询。

SELECT DISTINCT TC.V_ID, A.ID, A.NAME 
FROM OM_A_DATA TC 
INNER JOIN ACC_DOM_EXT AE ON TC.DOMAINS = AE.DOMAIN
INNER JOIN DATA_ACC_MAP AD ON TC.V_ID != AD.V_ID 
LEFT OUTER JOIN ACCOUNT A ON A.ID = AE.ACCOUNTID

或使用 LEFT JOIN 而不是子查询和更改的 WHERE 子句。

SELECT DISTINCT TC.V_ID, A.ID, A.NAME 
FROM OM_A_DATA TC 
INNER JOIN ACC_DOM_EXT AE ON TC.DOMAINS = AE.DOMAIN
LEFT JOIN DATA_ACC_MAP AD ON TC.V_ID = AD.V_ID 
LEFT OUTER JOIN ACCOUNT A ON A.ID = AE.ACCOUNTID
WHERE AD.V_ID IS NULL

SQL 查询时间过长

SQL Query is taking long time

sql

oracle

performance

oracle11g

sql-tuning