多项选择题
A.The leaf blocks in the index are doubly linked.
B.The leaf node stores a bitmap for each key value.
C.The rows with NULL value in key columns also have entries in the index.
D.The deletion of a row from the table causes a logical deletion in index leaf block and the space becomes available for the new leaf entry.
单项选择题 Whichstatementdescribestheeffectonanindex，whentheindexedcolumnfortherowsisupdatedinthebasetable（）
多项选择题 The session of user SCOTT receives the following error after executing an UPDATE command onthe EMP table： ERROR at line 1： ORA-00060： deadlock detected while waiting for resource On investigation， you find that a session opened by user JIM has a transaction that caused the deadlock. two statements are true regarding the session of SCOTT in this scenario（）
单项选择题 The table contains a million rows for zonewise analysis in the DSS system. DML operations areperformed very rarely on the table. You decide to prepare an index on the ZONE column to enhance theperformance of the queries on the ZONE column. Which type of index would you select in this scenario（）