提高数据加载效率

1. 先让约束条件无效，数据加载完后，让其有效

Ø Drop or Disable 外键约束会提高加载效率

SELECT 'ALTER TABLE ' || OWNER || '.' || TABLE_NAME || ' DISABLE CONSTRAINT ' || CONSTRAINT_NAME || ' ;'

FROM USER_CONSTRAINTS

WHERE (TABLE_NAME LIKE '%DIM' OR TABLE_NAME LIKE '%FACT')

AND CONSTRAINT_TYPE = 'R'

输出的结果是：

ALTER TABLE MDDB_DEV.AGREEMENT_DIM DISABLE CONSTRAINT SYS_C0011077 ;

ALTER TABLE MDDB_DEV.AGREEMENT_DIM DISABLE CONSTRAINT SYS_C0011075 ;

ALTER TABLE MDDB_DEV.CUSTOMER_DIM DISABLE CONSTRAINT SYS_C0011060 ;

ALTER TABLE MDDB_DEV.CUSTOMER_DIM DISABLE CONSTRAINT SYS_C0011059 ;

ALTER TABLE MDDB_DEV.CUSTOMER_SALES_FACT DISABLE CONSTRAINT SYS_C0011133 ;

ALTER TABLE MDDB_DEV.CUSTOMER_SALES_FACT DISABLE CONSTRAINT SYS_C0011134 ;

ALTER TABLE MDDB_DEV.CUSTOMER_SALES_FACT DISABLE CONSTRAINT SYS_C0011131

Ø Drop or Disable主键约束

SELECT 'ALTER TABLE ' || OWNER || '.' || TABLE_NAME || ' DISABLE PRIMARY KEY ;'

FROM USER_CONSTRAINTS

WHERE (TABLE_NAME LIKE '%DIM' OR TABLE_NAME LIKE '%FACT')

AND CONSTRAINT_TYPE = 'P'

输出的结果：

ALTER TABLE MDDB_DEV.AGREEMENT_DIM DISABLE PRIMARY KEY ;

ALTER TABLE MDDB_DEV.CUSTOMER_DIM DISABLE PRIMARY KEY ;

ALTER TABLE MDDB_DEV.CUSTOMER_SALES_FACT DISABLE PRIMARY KEY ;

Ø Drop or Disable 唯一约束

SELECT 'ALTER TABLE ' || OWNER || '.' || TABLE_NAME || ' DISABLE PRIMARY KEY ;'

FROM USER_CONSTRAINTS

WHERE (TABLE_NAME LIKE '%DIM' OR TABLE_NAME LIKE '%FACT')

AND CONSTRAINT_TYPE = 'U'

ALTER TABLE MDDB_DEV.CUSTOMER_DIM DISABLE CONSTRAINT SYS_C0011070 ;

ALTER TABLE MDDB_DEV.CUSTOMER_SALES_FACT DISABLE CONSTRAINT SYS_C0011071 ;