单选题You find this query being used in your Oracle 12c database: Which method a used by the optimizer to limit the rows being returned?（）AA filter is added to the table query dynamically using ROWNUM to limit the rows to 20 percent of the total rowsBAll the rows are returned to the client or middle tier but only the first 20 percent are returned to the screen or the application.CA view is created during execution and a filter on the view limits the rows to 20 percent of the total rows.DA TOP-N query is created to limit the rows to 20 percent of the total rows
单选题
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
参考解析
解析：
暂无解析
相关考题：
You want to use the Flashback Transaction Query feature to identify all the changes made to your database within a specific time period. What is a prerequisite for using the Flashback Transaction Query feature？（）A、 You must use automatic undo management in the database.B、 You must configure OMF in your database.C、 You must configure ASM for storing the datafiles.D、 You must multiplex the online redo log file.
You work as a database administrator for Certkiller .com. You want to administer your database servers，which are running on different host machines，using the Web-enabled grid control interface. You have configured the agent on the host machines. You have started the Oracle Database 10g Grid Control utility on your machine. Which two additional components would you configure to achieve this objective？（）A、Application Server ControlB、Oracle Management ServiceC、Oracle Enterprise Manager RepositoryD、Oracle Enterprise Manager Database Control
In your production database， you have observed that the database server performance degrades whenever there is a switch between the log groups. On further investigation， you find that the database is running in ARCHIVELOG mode and the archived log files are being written to the same disk that is used to store the redo log members. Which two actions would you take to improve the performance of the database server？（）A、increase the size of the redo log bufferB、increase the number of redo log groupsC、increase the number of log writer processesD、increase the number of ARCn processesE、change the appropriate LOG_ARCHIVE_DEST_n parameter to place the archived log files in a separate location
Your Oracle Database 10g is online when you execute the following statement： SQLALTER TABLESPACE MY_TABLESPACE FLASHBACK OFF； What is the result of executing this statement if the Flashback Database feature is already enabled in the database？（）A、 The database does not record flashback logs for MY_TABLESPACEB、 The tables residing in MY_TABLESPACE are not protected by the Recycle Bin.C、 All the tablespaces except MY_TABLESPACE can be recovered using Flashback Database feature.D、 None of the flashback technologies， such as Flashback Table， Flashback Transaction Query and Flashback Version Query can be used to recover individual rows within the objects from MY_TABLESPACE
Examine the parameter for your database instance: You generated the execution plan for the following query in the plan table and noticed that the nested loop join was done. After actual execution of the query, you notice that the hash join was done in the execution plan: Identify the reason why the optimizer chose different execution plans.（）A、The optimizer used a dynamic plan for the query.B、The optimizer chose different plans because automatic dynamic sampling was enabled.C、The optimizer used re-optimization cardinality feedback for the query.D、The optimizer chose different plan because extended statistics were created for the columns used.
You are maintaining your database in Oracle10g. You find that the number of languages that should be supported in your database has increased. The character set of your database is UTF8. You decide to migrate your database to the AL16UTF16 national character set. How will you migrate your database from UTF8 to AL16UTF16？（） A、 by using the RMAN utilityB、 by using the export/import utilityC、 by using the ALTER DATABASE commandD、 by enabling the change tracking feature
You are maintaining your OLTP database in Oracle10g. You are performing the Flashback Transaction Query to find the undo SQL statements that can be used to undo the changes made to the database in the specific time period. Which pseudocolumn will you use to perform the Flashback Transaction Query？（）A、 VERSIONS_STARTSCNB、 VERSIONS_STARTTIMEC、 VERSIONS_XIDD、 VERSIONS_OPERATION
You want to create a new optimized database for your transactional production environment to be used by a financial application. While creating the database， you want the Oracle software to take care of all basic settings to optimize the database performance. Which method would you use to achieve this objective？（）A、Use the CREATE DATABASE .. command to create the database with Oracle-managed files. B、Use the Database Configuration Assistant (DBCA) to create the database with Oracle-managed files. C、Use Enterprise Manager to create a new database with the Online Transaction Processing (OLTP) option. D、Use Database Configuration Assistant (DBCA) to create the database with Transaction Processing template. E、Use the CREATE DATABASE .. command to create the database with Automatic Storage Management (ASM) file system.
You are maintaining your database in Oracle10g. You are not using the recovery catalog to maintain the backup information of your database. Which file can be used as a repository to store information regarding the RMAN backup？（）A、 online redo log filesB、 alert log filesC、 control fileD、 datafiles associated with the SYSTEM tablespace
You executed the following query in your database： FROM V$FLASHBACK_DATABASE_LOG; What would you determine from the output？（）A、the time when the last flashback operation in your database was performedB、the time when the first flashback operation in your database was performedC、a list of flashback operations performed in your database using SCN and timeD、the approximate time and the lowest system change number （SCN） to which you can flash back your database
You are maintaining your database in Oracle10g. You find that the INDEXES index tablespace should be recovered. How will you recover the index tablespace？（）A、 by using the Flashback Database featureB、 by using RMAN incomplete recoveryC、 by performing a user-managed incomplete recoveryD、 by dropping and re-creating the index tablespace
You are required to flashback your database. You want to find the amount of flashback data generated since the database was opened. Which task will you perform to obtain the required information？（）A、 Query the V$FLASHBACK_DATABASE_LOG view.B、 Query the V$FLASHBACK_DATABASE_STAT view.C、 Check the value of the DB_FLASHBACK_RETENTION_TARGET initialization parameter.D、 Query the V$RECOVERY_FILE_DEST view.
Your database instance is running. You are not able to access Oracle Enterprise Manager Database Control because the listener is not started. Which tool or utility would you use to start the listener？（）A、 Oracle Net ManagerB、 Listener Control utilityC、 Database Configuration AssistantD、 Oracle Net Configuration Assistant
You are installing Oracle Database 11g on your server. During the installation Oracle Universal Installer （OUI） prompts you to enter the path of the inventory directory and also prompts you to specify an operating systemgroup name. Which statement is true in this case（）A、The ORACLE_BASE parameter is not set.B、The installation is being performed by the root user.C、The operating system group that will be specified should have root user as its member.D、The installation is being performed without the "Create Starter Database" option selected.E、The operating system group that will be specified must have permission to write to the inventory directory
You are a database administrator for your company. The company uses a vendor company’s application that is based on a proprietary database. You query data from the application database and import the data into a SQL Server 2005 database. The application vendor provides you with a new OLE DB driver to be used when querying the application database. Company policy prohibits connections between the SQL Server database and the application database， except when querying this data. You need to provide a way to query data from the application database. What should you？（）A、Configure a Linked Server connection to the application database.B、Write a query that uses an OPENDATASOURCE command.C、Write a query that uses an OPENQUERY command.D、Configure a Remote Server connection to the application database.
单选题You are maintaining your OLTP database in Oracle10g. You are performing the Flashback Transaction Query to find the undo SQL statements that can be used to undo the changes made to the database in the specific time period. Which pseudocolumn will you use to perform the Flashback Transaction Query？（）A VERSIONS_STARTSCNB VERSIONS_STARTTIMEC VERSIONS_XIDD VERSIONS_OPERATION
单选题You want to use the Flashback Transaction Query feature to identify all the changes made to your database within a specific time period. What is a prerequisite for using the Flashback Transaction Query feature？（）A You must use automatic undo management in the database.B You must configure OMF in your database.C You must configure ASM for storing the datafiles.D You must multiplex the online redo log file.
单选题In your datawarehousing application， you generate reports frequently. The data is static in the tables being used to generate reports. You are currently using joins， resulting in a large performance overhead. What kind of database structure would you use to reduce the response time of the query？（）Ahash clustersBindex clustersCpartitioned tablesDindexorganized table （IOT）
单选题You are maintaining your database in Oracle10g. You are not using the recovery catalog to maintain the backup information of your database. Which file can be used as a repository to store information regarding the RMAN backup？（）A online redo log filesB alert log filesC control fileD datafiles associated with the SYSTEM tablespace
多选题In your production database， you have observed that the database server performance degrades whenever there is a switch between the log groups. On further investigation， you find that the database is running in ARCHIVELOG mode and the archived log files are being written to the same disk that is used to store the redo log members. Which two actions would you take to improve the performance of the database server？（）Aincrease the size of the redo log bufferBincrease the number of redo log groupsCincrease the number of log writer processesDincrease the number of ARCn processesEchange the appropriate LOG_ARCHIVE_DEST_n parameter to place the archived log files in a separate location
单选题You are maintaining your database in Oracle10g. You find that the INDEXES index tablespace should be recovered. How will you recover the index tablespace？（）A by using the Flashback Database featureB by using RMAN incomplete recoveryC by performing a user-managed incomplete recoveryD by dropping and re-creating the index tablespace
单选题Your Oracle Database 10g is online when you execute the following statement： SQLALTER TABLESPACE MY_TABLESPACE FLASHBACK OFF； What is the result of executing this statement if the Flashback Database feature is already enabled in the database？（）A The database does not record flashback logs for MY_TABLESPACEB The tables residing in MY_TABLESPACE are not protected by the Recycle Bin.C All the tablespaces except MY_TABLESPACE can be recovered using Flashback Database feature.D None of the flashback technologies， such as Flashback Table， Flashback Transaction Query and Flashback Version Query can be used to recover individual rows within the objects from MY_TABLESPACE
单选题You are maintaining your database in Oracle10g. You find that the number of languages that should be supported in your database has increased. The character set of your database is UTF8. You decide to migrate your database to the AL16UTF16 national character set. How will you migrate your database from UTF8 to AL16UTF16？（）A by using the RMAN utilityB by using the export/import utilityC by using the ALTER DATABASE commandD by enabling the change tracking feature
单选题You are connecting to an Oracle database server from a client by using the following connect string： SQL CONNECT hr/hr@pdserver.us.oracle.com：1521/proddb Which naming method is being used in this case？（）ALocal NamingBEasy ConnectCExternal NamingDDirectory Naming
单选题You have many users complaining about slow inserts into a large table. While investigating the reason， you find that the number of indexes on the table is high. You want to find out which indexes are not being used. Which method would you follow to achieve this？（）Aenable index monitoring and query the DBA_OBJECTS viewBenable index monitoring and query the DBA_INDEXES viewCenable index monitoring and query the V$OBJECT_USAGE viewDenable index monitoring and view the DBA_INDEXTYPE_COMMENTS view
单选题You executed the following query in your database： FROM V$FLASHBACK_DATABASE_LOG; What would you determine from the output？（）Athe time when the last flashback operation in your database was performedBthe time when the first flashback operation in your database was performedCa list of flashback operations performed in your database using SCN and timeDthe approximate time and the lowest system change number （SCN） to which you can flash back your database
单选题You find this query being used in your Oracle 12c database: Which method a used by the optimizer to limit the rows being returned?（）AA filter is added to the table query dynamically using ROWNUM to limit the rows to 20 percent of the total rowsBAll the rows are returned to the client or middle tier but only the first 20 percent are returned to the screen or the application.CA view is created during execution and a filter on the view limits the rows to 20 percent of the total rows.DA TOP-N query is created to limit the rows to 20 percent of the total rows
单选题You are required to flashback your database. You want to find the amount of flashback data generated since the database was opened. Which task will you perform to obtain the required information？（）A Query the V$FLASHBACK_DATABASE_LOG view.B Query the V$FLASHBACK_DATABASE_STAT view.C Check the value of the DB_FLASHBACK_RETENTION_TARGET initialization parameter.D Query the V$RECOVERY_FILE_DEST view.