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 rowsB、All the

题目

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
相似考题

1.View the Exhibit for some of the parameter settings. You start a session and issue the following command:SQL>CREATE INDEX emp_ename ON emp(ename) TABLESPACE users INVISIBLE;What is the outcome of the above command?（）A. The index is not used by the optimizer but is maintained during DML operations.B. The index is not used by the optimizer and is not maintained during DML operations.C. The index is used by the optimizer only if a hint is specified in the query statement and is maintained during DML operations.D. The index is used by the optimizer only if a hint is specified in the query statement but is not maintained during DML operations.

2.EIGRP is being used as the routing protocol on the PassGuide network. Whiletroubleshooting some network connectivity issues，you notice a large number of EIGRP SIA（StuckinActive）messages. What causes these SIA routes（）A、The neighboring router stops receiving ACK packets from this router.B、The neighboring router starts receiving route updates from this router.C、The neighboring router is too busy to answer the query(generally caused by high CPU utilization).D、The neighboring router is having memory problems and cannot allocate the memory to process the query or build the reply packet.

3.You have been assigned to manage a set of databases. The previous DBA did not leave you notes regarding the structure of each of the databases. While analyzing an instance， you notice that the system identifier （SID） for the instance is set to ’+ASM’. What is the purpose of this instance？（）A、 This instance is being used to manage the operating system files.B、 This instance is being used to manage the files of other databases.C、 This instance is being used to manage the instances of other databases.D、 This instance is being used to manage the background processes of other instances.

4.You define a multiple－row subquery in the WHERE clause of an SQL query with a comparison operator "=". What happens when the main query is executed? ()A. The main query executes with the first value returned by the subquery.B. The main query executes with the last value returned by the subquery.C. The main query executes with all the values returned by the subquery.D. The main query fails because the multiple-row subquery cannot be used with the comparison operator.E. You cannot define a multiple-row subquery in the WHERE clause of a SQL query.

参考答案和解析
正确答案:C
更多“You find this query being used ”相关问题

  • 第1题：

    EIGRP is being used as the routing protocol on the company network. While troubleshooting somenetwork connectivity issues， you notice a large number of EIGRP SIA （Stuck in Active） messages.What causes these SIA routes？（）

    • A、The neighboring router stops receiving ACK packets from this router
    • B、The neighboring router starts receiving route updates from this router
    • C、The neighboring router is too busy to answer the query （generally caused by high CPUutilization）
    • D、The neighboring router is having memory problems and cannot allocate the memory to processthe query or build the reply packet

    正确答案:C,D

  • 第2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_STARTSCN
    • B、 VERSIONS_STARTTIME
    • C、 VERSIONS_XID
    • D、 VERSIONS_OPERATION

    正确答案:C

  • 第3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.

    正确答案:B

  • 第4题：

    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.

    正确答案:B

  • 第5题：

    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_STARTSCN

    B

     VERSIONS_STARTTIME

    C

     VERSIONS_XID

    D

     VERSIONS_OPERATION


    正确答案： A
    解析： 暂无解析

  • 第6题：

    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？（）
    A

    hash clusters

    B

    index clusters

    C

    partitioned tables

    D

    index­organized table （IOT）


    正确答案： B
    解析： 暂无解析

  • 第7题：

    单选题
    You have been assigned to manage a set of databases. The previous DBA did not leave you notes regarding the structure of each of the databases. While analyzing an instance， you notice that the system identifier （SID） for the instance is set to ’+ASM’. What is the purpose of this instance？（）
    A

     This instance is being used to manage the operating system files.

    B

     This instance is being used to manage the files of other databases.

    C

     This instance is being used to manage the instances of other databases.

    D

     This instance is being used to manage the background processes of other instances.


    正确答案： C
    解析： 暂无解析

  • 第8题：

    多选题
    EIGRP is being used as the routing protocol on the PassGuide network. Whiletroubleshooting some network connectivity issues，you notice a large number of EIGRP SIA（StuckinActive）messages. What causes these SIA routes（）
    A

    The neighboring router stops receiving ACK packets from this router.

    B

    The neighboring router starts receiving route updates from this router.

    C

    The neighboring router is too busy to answer the query(generally caused by high CPU utilization).

    D

    The neighboring router is having memory problems and cannot allocate the memory to process the query or build the reply packet.


    正确答案： A,B
    解析： 暂无解析

  • 第9题：

    多选题
    EIGRP is being used as the routing protocol on the company network. While troubleshooting somenetwork connectivity issues， you notice a large number of EIGRP SIA （Stuck in Active） messages.What causes these SIA routes？（）
    A

    The neighboring router stops receiving ACK packets from this router

    B

    The neighboring router starts receiving route updates from this router

    C

    The neighboring router is too busy to answer the query （generally caused by high CPUutilization）

    D

    The neighboring router is having memory problems and cannot allocate the memory to processthe query or build the reply packet


    正确答案： A,D
    解析： 暂无解析

  • 第10题：

    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？（）
    A

    enable index monitoring and query the DBA_OBJECTS view

    B

    enable index monitoring and query the DBA_INDEXES view

    C

    enable index monitoring and query the V$OBJECT_USAGE view

    D

    enable index monitoring and view the DBA_INDEXTYPE_COMMENTS view


    正确答案： A
    解析： 暂无解析

  • 第11题：

    单选题
    View the Exhibits. You performed operations on the DEPT4 table as shown in the Exhibit. When you perform the FlashbackVersions Query， you find that the first two updates are not listed. What could be the reason？（）
    A

    The row movement is not enabled on the table.

    B

    The first two updates were not explicitly committed.

    C

    The Flashback Versions Query lists only the most recent update.

    D

    The Flashback Versions Query stops producing rows after it encounters a time in the past when the  table structure was changed.


    正确答案： B
    解析： 暂无解析

  • 第12题：

    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.


    正确答案： D
    解析： 暂无解析

  • 第13题：

    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.

    正确答案:B

  • 第14题：

    You issued the following statement to monitor the usage of the index：        SQL> ALTER INDEX SCOTT.EMP_IDX MONITORING USAGE；   Which view will you query to ensure that the index is being monitored？（）  

    • A、 INDEX_STATS
    • B、 DBA_INDEXES
    • C、 DBA_IND_COLUMNS
    • D、 V$OBJECT_USAGE

    正确答案:D

  • 第15题：

    You define a multiple-row subquery in the WHERE clause of an SQL query with a comparison operator "=".What happens when the main query is executed?（）

    • A、The main query executes with the first value returned by the subquery.
    • B、The main query executes with the last value returned by the subquery.
    • C、The main query executes with all the values returned by the subquery.
    • D、The main query fails because the multiple-row subquery cannot be used with the comparison operator.
    • E、You cannot define a multiple-row subquery in the WHERE clause of a SQL query.

    正确答案:D

  • 第16题：

    You are a professional level SQL Server 2005 database administrator in an international corporation named Wiikigo. You are experienced in implementing high-availability solutions， monitoring the database server， and design deployment. In the company， you major job is the deployment， maintenance and support of Microsoft SQL Server 2005.You work as a database administrator for your company. You find a problem that when the following query is executed， a SQL Server 2005 application will perform slowly. SELECT * FROM Orders WHERE OrderStatus = ’InProgress’ This query is executed by the application as an ad hoc query. In most occasions， this query performs much more quickly. The company has the OrderStatus column indexed. The value InProgress is included by only a small number of the rows. Nevertheless， the OrderStatus column index which is the most ideal for this query is not being utilized. The performance of this query should be enhanced. However， the application that executes the query should not be changed. In addition， the effect on end users should be cut to the least.  Which action should be performed to finish the task？（）

    • A、To finish the task， the index should be built by utilizing a FILLFACTOR of 10 percent.
    • B、To finish the task， the index should be recreated to have all of the columns in the table included.
    • C、To finish the task， an indexed view of the Orders table should be viewed.
    • D、To finish the task， the statistics should be updated on the index.

    正确答案:D

  • 第17题：

    单选题
    When does Oracle9i flag an index as being used in the V$OBJECT_USAGE view？（）
    A

    During a query’s parse time only. 

    B

    During a query’s execution time only. 

    C

    During any kind of DML statement execution. 

    D

    During the execution of an INSERT statement only.


    正确答案： A
    解析： 暂无解析

  • 第18题：

    单选题
    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？（）
    A

    run Segment Advisor

    B

    run SQL Tuning Advisor on top SQL statements

    C

    run the Automatic Workload Repository （AWR） report

    D

    run the Automatic Database Diagnostic Monitor （ADDM）on top SQL statements


    正确答案： D
    解析： 暂无解析

  • 第19题：

    单选题
    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.


    正确答案： A
    解析： 暂无解析

  • 第20题：

    单选题
    You define a multiple-row subquery in the WHERE clause of an SQL query with a comparison operator "=".What happens when the main query is executed?（）
    A

    The main query executes with the first value returned by the subquery.

    B

    The main query executes with the last value returned by the subquery.

    C

    The main query executes with all the values returned by the subquery.

    D

    The main query fails because the multiple-row subquery cannot be used with the comparison operator.

    E

    You cannot define a multiple-row subquery in the WHERE clause of a SQL query.


    正确答案： D
    解析： 暂无解析

  • 第21题：

    单选题
    In the second paragraph, the writer talks about someone saying “You are a lucky dog.” He is saying that ______.
    A

    the speaker of this sentence is just being friendly

    B

    “dog” can’t be used to refer to people

    C

    this saying means the same as “You are a lucky guy” or “you are a lucky gal”

    D

    sometimes the words used by a speaker give a clue to the feeling behind the words


    正确答案： A
    解析：
    文中提到“But bringing in the ‘dog’ he put you down a little. What he may be saying is that he doesn't think you deserve your luck”，即用dog这个词是把你放低了，他说的可能使你不配这种运气。D项“有时候说话者用的词暗示了话语之后的真正意思”，很好的阐述了这一点，D项正确。

  • 第22题：

    填空题
    Where can you find the correct amount of the detergent to be used?On ____.

    正确答案： your detergent box
    解析：
    从文章第一段第四句“you should read the directions on your detergent box to find out the correct amount for your particular load”可知，此处应填your detergent box。

  • 第23题：

    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


    正确答案： B
    解析： 暂无解析

  • 第24题：

    单选题
    Where will you find the requirements for the signals that must be sounded by a mobile offshore drilling unit that is being towed through an area of restricted visibility? （）
    A

    COLREGS

    B

    MMS Rules

    C

    SOLAS Convention

    D

    Coast Pilot


    正确答案： C
    解析： 暂无解析

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