94.You plan to move data from a flat file to a table in your database. You decide to use SQL*Loader

94.You plan to move data from a flat file to a table in your database. You decide to use SQL*Loader direct
path load method to perform this task. The table in which you plan to load data is an important table
having various integrity constraints defined on it.
Which constraints will remain enabled by default during this operation? (Choose all that apply.)
A.CHECK
B.UNIQUE
C.NOT NULL
D.PRIMARY KEY
E.FOREIGN KEY
答案：BCD
参考:
http://docs.oracle.com/cd/E11882_01/server.112/e22490/ldr_modes.htm#g1023818
http://docs.oracle.com/cd/E11882_01/server.112/e22490/ldr_modes.htm#SUTIL1283
When loading a relatively small number of rows into a large table with referential and column-check integrity constraints
Because these constraints cannot be applied to rows loaded on the direct path, they are disabled for the duration of the load. Then they are applied to the whole table when the load completes. The costs could outweigh the savings for a very large table and a small number of new rows.
因此，在loader过程中，check和外键是禁用了，到导入结束后，会启用