单项选择题
You find this query being used in your Oracle 12c database:
Which method a used by the optimizer to limit the rows being returned?（）
A. A filter is added to the table query dynamically using ROWNUM to limit the rows to 20 percent of the total rows
B. All the rows are returned to the client or middle tier but only the first 20 percent are returned to the screen or the application.
C. A view is created during execution and a filter on the view limits the rows to 20 percent of the total rows.
D. A TOP-N query is created to limit the rows to 20 percent of the total rows
相关考题
-
多项选择题
You performed an incremental level 0 backup of a database: RMAN > BACKUP INCREMENTAL LEVEL 0 DATABASE; To enable block change tracking after the incremental level 0 backup, you issued this command: SQL > ALTER DATABASE ENABLE BLOCK CHANGE TRACKING USING FILE ‘ /mydir/rman_change_track.f’; To perform an incremental level 1 cumulative backup, you issued this command: RMAN> BACKUP INCREMENTAL LEVEL 1 CUMULATIVE DATABASE; Which three statements are true?（）
A. Backup change tracking will sometimes reduce I/O performed during cumulative incremental backups.
B. The change tracking file must always be backed up when you perform a full database backup.
C. Block change tracking will always reduce I/O performed during cumulative incremental backups.
D. More than one database block may be read by an incremental backup for a change made to a single block.
E. The incremental level 1 backup that immediately follows the enabling of block change tracking will not read the change tracking file to discover changed blocks. -
多项选择题
Your multitenant container database (CDB) contains some pluggable databases (PDBs), you execute the following command in the root container: Which two statements are true?（）
A. Schema objects owned by the C# # A_ADMIN common user can be shared across all PDBs.
B. The C # # A_ADMIN user will be able to use the TEMP_TS temporary tablespace only in root.
C. The command will, create a common user whose description is contained in the root and each pdb.
D. The schema for the common user C # # A_ADMIN can be different in each container.
E. The command will create a user in the root container only because the container clause is not used -
单项选择题
Oracle Grid Infrastructure for a stand-alone server is installed on your production host before installing the Oracle Database server. The database and listener are configured by using Oracle Restart. Examine the following command and its output: $ crsctl config has CRS-4622: Oracle High Availability Services auto start is enabled. What does this imply?（）
A. When you start an instance on a high with SQL *Plus dependent listeners and ASM disk groups are automatically started.
B. When a database instance is started by using the SRVCTL utility and listener startup fails, the instance is still started.
C. When a database is created by using SQL* Plus, it is automatically added to the Oracle Restart configuration.
D. When you create a database service by modifying the SERVICE_NAMES initialization parameter, it is automatically added to the Oracle Restart configuration.
