You received complaints about the degradation of SQL query performance. You identified top SQL queries that consume time. What would be your next step to find out recommendations about statistics collection and restructuring of the SQL statement to improve query performance？（）

多项选择题Whichthreestatementsaretrueaboutthestagesofdatabasestartup？（）

A.Data files and redo log files can be renamed at the MOUNT stage.
B.Control files are read at the OPEN stage for the location of data files.
C.Control files are required to bring the database to the NOMOUNT stage.
D.Data files and redo log files are made available to users at the OPEN stage.
E.Data files and online redo log files are checked for consistency while opening the database

多项选择题Whichthreepiecesofinformationareconsideredwhiledecidingthesizeoftheundotablespaceinyourdatabase？（）

A.the size of an undo block
B.the size of the redo log files
C.undo blocks generated per second
D.the size of the database buffer cache
E.the value of the UNDO_RETENTION parameter

多项选择题You connected to the database using the following connection string： CONNECT hr hr@test.us.oracle.com：1521 mydb  Which three statements are correct regarding the connection string？（）

A.mydb is a service name.
B.test.us.oracle.com is a database name.
C.1521 is the listener port number.
D.mydb is a host name.
E.test.us.oracle.com is a net service name.
F.hr is a username.
G.test.us.oracle.com is an instance name.

单项选择题View the Exhibit to see the output of queries on DATABASEPROPERTIES and DBAUSERS. You observe that the current default permanent tablespace of the database is  running out of space and you decide to change it to NEWDEFTBSP. You create a new user， USER04， after changing the default permanent tablespace of the database. What would be the new user’s default tablespace？（）

A.DEFTBSP
B.SYSTEM
C.NEWDEFTBSP
D.USERS and NEWDEFTBSP both
E.USERS

多项选择题Identifythetwotablespaceswhosedatafilesaresocriticalthatonlyaclosedrecoveryispossible.（）

A.SYSAUX
B.TOOLS
C.UNDO
D.INDEX
E.SYSTEM
F.USERS
G.TEMP