多项选择题
A.It is recommended for the columns that have unique values.
B.It can be converted to a B-tree index by using the ALTER INDEX command.
C.It has a bitmap segment for each distinct value in the key column， containing a string of bits in which each bit represents the presence or absence of a key column value.
D.Updating the key column locks the whole bitmap segment that contains the bit for the key value to be updated.
单项选择题 Examine the following commands executed in your database： SQL> ALTER SESSION RECYCLEBIN=ON； Session altered SQL> CREATE TABLE emp TABLESPACE tbsfd AS SELECT * FROM hr.employees； Table created. Further， you executed the following command to drop the table： SQL> DROP TABLE emp； Table dropped. What happens in this scenario？ （）
单项选择题 You execute the following command to audit the database activities： SQL> AUDIT DROP ANY TABLE BY scott BY SESSION WHENEVER SUCCESSFUL； What is the effect of this command？（）
单项选择题 Youhavealargeamountofhistoricaldatainanoperatingsystemfile.Someanalystsinyourorganizationneedtoquerythisdata.Thefileistoolargetoloadintoyourcurrentdatabase.Whichisthemosteffectivemethodtoaccomplishthetask？（）