单项选择题 Which of the following DB2 tools allows a user to execute an SQL statement and view a graphical representation of the access plan?（）

单项选择题 Application A currently holds an exclusive lock on a single row and application B tries to access that row. If lock timeout is set to -1 and both applications are using isolation level RS, which of the following will occur?（）

单项选择题 How does DB2 protect the integrity of indexes when data is updated?（）