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：
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.
Which of the following statements best describes Flashback Versions Query？（） A、 Flashback Versions Query is used to make changes to multiple versions of data that existed between two points in time.B、 Flashback Versions Query is used to view all version changes on rows that existed between the time the query was executed and a point in time in the past.C、 Flashback Versions Query is used to view version changes and the SQL to undo those changes on rows that existed between two points in time.D、 Flashback Versions Query is used to view all version changes on rows that existed between two points in time.
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
A warehouse fact table in your Oracle 12c Database is range-partitioned by month and accessed frequently with queries that span multiple partitions The table has a local prefixed, range partitioned index. Some of these queries access very few rows in some partitions and all the rows in other partitions, but these queries still perform a full scan for all accessed partitions. This commonly occurs when the range of dates begins at the end of a month or ends close to the start of a month. You want an execution plan to be generated that uses indexed access when only a few rows are accessed from a segment, while still allowing full scans for segments where many rows are returned. Which three methods could transparently help to achieve this result?（）A、Using a partial local Index on the warehouse fact table month column with indexing disabled to the table partitions that return most of their rows to the queries.B、Using a partial local Index on the warehouse fact table month column with indexing disabled for the table partitions that return a few rows to the queries.C、Using a partitioned view that does a UNION ALL query on the partitions of the warehouse fact table, which retains the existing local partitioned column.D、Converting the partitioned table to a partitioned view that does a UNION ALL query on the monthly tables, which retains the existing local partitioned columnE、Using a partial global index on the warehouse fact table month column with indexing disabling for the table partitions that return most of their rows to the queries.F、Using a partial global index on the warehouse fact table month column with indexing disabled for the table partitions that return a few rows to the queries.
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.
Which two statements are true about WHERE and HAVING clauses? （）A、A WHERE clause can be used to restrict both rows and groups.B、A WHERE clause can be used to restrict rows only.C、A HAVING clause can be used to restrict both rows and groups.D、A HAVING clause can be used to restrict groups only.E、A WHERE clause CANNOT be used in a query of the query uses a HAVING clause.F、A HAVING clause CANNOT be used in subqueries.
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 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 viewB、enable index monitoring and query the DBA_INDEXES viewC、enable index monitoring and query the V$OBJECT_USAGE viewD、enable index monitoring and view the DBA_INDEXTYPE_COMMENTS view
You work as a database administrator for Supportcenter.cn. One of the database users accidentally deleted all the rows of a critical table and committed the delete at 1：30 p.m. You senior database administrator， SupportCenter， asks you to retrieve the lost data. Which two actions would you use to ensure that there is no impact on other connected users while retrieving the deleted rows？（）A、Use a flashback query to retrieve the rows that were deletedB、Useconventialincremental export and then import the affected objectC、Shutdown the database inNORMALmode and restart the database instanceD、Use DBMS_META package to reconstruct the object using undo segmentsE、UseTablespacePoint in Time Recovery （TSPITR） method to recover the table and the dataF、Use Oracle DataPumptwithflashback_timeoption toentableflashback export and then import the affected object.
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？（）A、Local NamingB、Easy ConnectC、External NamingD、Directory Naming
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 clustersB、index clustersC、partitioned tablesD、indexorganized table （IOT）
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 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
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.
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. A SQL Server 2005 application is utilized by the company. A query is executed by the application to return three columns of the nvarchar data type and one column of the XML data type. A WHERE clause is utilized by the query， and all three of the nvarchar columns are contained by the WHERE clause. 5 million rows are included by the table， and 50，000 rows are returned by the query. The performance of the query should be enhanced. Which action should be performed to achieve the goal？（）A、A primary XML index should be created on the XML column.B、Statistics should be created on the nvarchar columns.C、A view should be created， and only the four columns that the query utilizes are contained by a view.D、A composite index should be created on the three nvarchar columns， and INCLUDE should be specified for the XML column.
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. A SQL Server 2005 computer is managed by you， and a database named Customers is included by the SQL Server 2005 computer. A table named CustInfo is included by the database. An identity column named CustID and an nvarchar column named CustName are included by the table. According to the company requirement， rows which duplicate CustName values are included should be moved from the CustInfo table every year. However， the company requests to have rows removed from the CustInfo table after the rows have been manually examined and verified as being duplicates. Since you are the technical support， you are required to think out a method to have potential duplicate rows identified for manual examination. The minimum amount of administrative effort should be utilized. Which action should be performed to finish the task？（）A、A trigger should be created for the CustInfo table so as to roll back INSERT queries that duplicate data is included.B、A new unique index should be created on the CustName column. And then， IGNORE_DUP_KEY = ON should be specified when creating index.C、On the CustName column， a foreign key constraint should be created， and a distinct list of CustName values is referenced by the foreign key constraint.D、A SELECT INTO query should be utilized， and GROUP BY and HAVING clauses should be included by the query to create a new table that contains duplicate rows from the CustInfo table.
单选题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？（）ATo finish the task， the index should be built by utilizing a FILLFACTOR of 10 percent.BTo finish the task， the index should be recreated to have all of the columns in the table included.CTo finish the task， an indexed view of the Orders table should be viewed.DTo finish the task， the statistics should be updated on the index.
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 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Which of the following statements best describes Flashback Versions Query？（）A Flashback Versions Query is used to make changes to multiple versions of data that existed between two points in time.B Flashback Versions Query is used to view all version changes on rows that existed between the time the query was executed and a point in time in the past.C Flashback Versions Query is used to view version changes and the SQL to undo those changes on rows that existed between two points in time.D Flashback Versions Query is used to view all version changes on rows that existed between two points in time.
多选题You work as a database administrator for Certkiller .com. One of the database users accidentally deleted all the rows of a critical table and committed the delete at 1：30 p.m. You senior database administrator， Certkiller， asks you to retrieve the lost data. Which two actions would you use to ensure that there is no impact on other connected users while retrieving the deleted rows？（）AUse a flashback query to retrieve the rows that were deletedBUseconventialincremental export and then import the affected objectCShutdown the database inNORMALmode and restart the database instanceDUse DBMS_META package to reconstruct the object using undo segmentsEUseTablespacePoint in Time Recovery （TSPITR） method to recover the table and the dataFUse Oracle DataPumptwithflashback_timeoption toentableflashback export and then import the affected object.
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.（）AThe optimizer used a dynamic plan for the query.BThe optimizer chose different plans because automatic dynamic sampling was enabled.CThe optimizer used re-optimization cardinality feedback for the query.DThe optimizer chose different plan because extended statistics were created for the columns used.
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By mistake， you ran the batch job （for updating the BILL_DETAILS table） twice. You are not sure which rows in the BILL_DETAILS table were affected. You need to identify： a） a list of changes made along with the transaction identifier of each change b） the necessary SQL statements to undo the erroneous changes Which option would you choose？（）ARMAN onlyBFlashback Table onlyCFlashback Versions Query onlyDFlashback Database and Flashback Transaction QueryEFlashback Versions Query and Flashback Transaction Query
多选题A warehouse fact table in your Oracle 12c Database is range-partitioned by month and accessed frequently with queries that span multiple partitions The table has a local prefixed, range partitioned index. Some of these queries access very few rows in some partitions and all the rows in other partitions, but these queries still perform a full scan for all accessed partitions. This commonly occurs when the range of dates begins at the end of a month or ends close to the start of a month. You want an execution plan to be generated that uses indexed access when only a few rows are accessed from a segment, while still allowing full scans for segments where many rows are returned. Which three methods could transparently help to achieve this result?（）AUsing a partial local Index on the warehouse fact table month column with indexing disabled to the table partitions that return most of their rows to the queries.BUsing a partial local Index on the warehouse fact table month column with indexing disabled for the table partitions that return a few rows to the queries.CUsing a partitioned view that does a UNION ALL query on the partitions of the warehouse fact table, which retains the existing local partitioned column.DConverting the partitioned table to a partitioned view that does a UNION ALL query on the monthly tables, which retains the existing local partitioned columnEUsing a partial global index on the warehouse fact table month column with indexing disabling for the table partitions that return most of their rows to the queries.FUsing a partial global index on the warehouse fact table month column with indexing disabled for the table partitions that return a few rows to the queries.
多选题Which two statements are true about WHERE and HAVING clauses? （）AA WHERE clause can be used to restrict both rows and groups.BA WHERE clause can be used to restrict rows only.CA HAVING clause can be used to restrict both rows and groups.DA HAVING clause can be used to restrict groups only.EA WHERE clause CANNOT be used in a query of the query uses a HAVING clause.FA HAVING clause CANNOT be used in subqueries.
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