You create a table in your database that contains 50,000 row

题目
单选题
You create a table in your database that contains 50,000 rows approximately. The queries performed on the table are complex and performed on the table frequently. Which advisor helps you achieve the best performance of database for queries by recommending the appropriate indexes?()
A

SQL Access Advisor

B

 Memory Advisor

C

SQL Tuning Advisor

D

 Segment Advisor

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相似问题和答案

第1题:

The database administrator of your company created a public synonym called HR for the HUMAN_RESOURCES table of the GENERAL schema, because many users frequently use this table. As a user of the database, you created a table called HR in your schema. What happens when you execute this query? SELECT * FROM HR; ()

  • A、You obtain the results retrieved from the public synonym HR created by the database administrator.
  • B、You obtain the results retrieved from the HR table that belongs to your schema.
  • C、You get an error message because you cannot retrieve from a table that has the same name as a public synonym.
  • D、You obtain the results retrieved from both the public synonym HR and the HR table that belongs to your schema, as a Cartesian product.
  • E、You obtain the results retrieved from both the public synonym HR and the HR table that belongs to your schema, as a FULL JOIN.

正确答案:B

第2题:

You are a database administrator for your company. The company uses a SQL Server 2005 database that includes a table named Inventory. The table contains a column named Price. A company policy states that the value in the Price column cannot be decreased by more than 10 percent in any single database operation. Updates to the Price column are made by various means, including by using ad hoc queries. You need to ensure that this company policy is enforced. What should you do?()

  • A、Create a trigger that rolls back changes to the Price column that violate company policy.
  • B、Create a stored procedure that disallows changes to the Price column that violate company policy.
  • C、On the Price column, create a check constraint that requires a specified minimum value.
  • D、On the Price column, create a foreign key constraint to a table that contains valid prices.

正确答案:A

第3题:

You are the administrator of a SQL Server 2000 database. You import a table of geographic information from a Microsoft access database into a SQL Server 2000 database. The table has 12,000 rows. Each row averages 5,000 bytes. The table contains lockup data that does not change.

You want to minimize the size of the data file and the time required to back up the data. Which two actions should you take? (Each correct answer presents part of the solution. Choose two)

A. Create a 60-MB data file named geography.ndf

B. Create a 95-MB data file named geography.ndf

C. Create a 60-MB data file named geography.mdf

D. Create a 95-MB data file named geography.mdf

E. Place the table in the PRIMARY filegroup.

F. Place the table in a new filegroup named LOCATION.


正确答案:BF
B,F 解析:Explanation: As SQL Server 2000 supports backing up or restoring individual files or file groups within a database, it is possible to reduce back up time by creating a separate data file table so that only that table will be backed up. This separate data file will have to be a secondary data file because a database can only have one primary data file, which is identified by the .mdf extension, it is the starting point of the database and locates all the other files in the database. Secondary data files are identified by the .ndf extension and comprise all of the data files except the primary data file. A database need not have a secondary data file and it is also possible to create multiple secondary data files on database.

Rows are stored in data pages. Rows cannot cross different data pages. The size of data page in SQL Server 2000 (or SQL 7.0) is 8,192 bytes. We can only store one row in every data page in this scenario. Thus, to estimate the size of the tale we would need to multiply the number of rows, 12,000 in this scenario, by 8,192 bytes. This will give us a table size of 98,304,000 bytes. As computer data storage is calculated using the binary rather than the decimal system, there is 1,024 bytes per Kb and 1,024 Kb per MB, rather than 1,000 bytes per Kb and 1,000 Kb per MB, we thus require a database size of at least 93.75 MB.

Incorrect Answers:
A: The data size of this table is insufficient as a minimum size of 93.75 MB is required.

C: The data size of this table is insufficient as a minimum size of 93.75 MB is required. Furthermore, the .mdf file extension indicate in this solution implies that the data file will be placed in the primary filegroup. It would thus not be possible to backup the data file pertaining to the table only.

D: The .mdf file extension indicate in this solution implies that the data file will be placed in the primary filegroup. It would thus not be possible to backup the data file pertaining to the table only.

E: As SQL Server 2000 supports backing up or restoring individual files or file groups within a database, it is possible to reduce back up time by creating a separate data file table so that only that table will be backed up. This separate data file will have to be a secondary data file because a database can only have one primary data file, which is identified by the .mdf extension, it is the starting point of the database and locates all the other files in the database.

第4题:

You create a table in your database that contains 50,000 rows approximately. The queries performed on the table are complex and performed on the table frequently. Which advisor helps you achieve the best performance of database for queries by recommending the appropriate indexes?()  

  • A、SQL Access Advisor
  • B、 Memory Advisor
  • C、SQL Tuning Advisor
  • D、 Segment Advisor

正确答案:A

第5题:

You work as a database administrator for Certkiller .com. In your transaction application, you have scheduled a job to update the optimizer statistics at05:00 pm every Friday. The job has successfully completed. Which three pieces of information would you check to confirm that the statistics have been collected?()

  • A、Average row size
  • B、Last analyzed date
  • C、Size of table in bytes
  • D、Size of table in database blocks
  • E、Number of free blocks in the free list
  • F、Number of extents present in the table.

正确答案:A,B,D

第6题:

You are planning to import customer data from the Customer table and the Country table in your SQL Server 2000 database into a SQL Server 2005 database. You want to ensure that during the import process,each value in the CountryCode column of the Customer table has a corresponding record in the CountryCode column in the Country table of the SQL Server 2005 database. You define a foreign key between these two tables. Thus,referential integrity will guarantee that the import routine fails if there are any records where a CountryCode value does not exist in the Country table but does exist in the Customer table. You need to ensure that the import process does not fail if records are encountered that do not exist in the Country table. What should you do?()

  • A、Drop the foreign key. Import the data by using the script. Re-create the foreign key.
  • B、Create a CHECK constraint.
  • C、Create a DML INSTEAD OF trigger that writes the failed records to a file or table.
  • D、Create a DML AFTER trigger that writes the failed records to a file or table.

正确答案:C

第7题:

You find today’s performance of your production database to be the best ever. Therefore, you want to be notified in the future whenever the performance degrades by 10% of today’s performance. What is the first step that you would take to ensure this?()

  • A、create baseline metrics for today’s performance
  • B、write the current database metrics to a database table and create a trigger to compare with future database statistics
  • C、write the current database metrics to a flat file and create an operating script to compare with future database statistics
  • D、write the current database metrics to a database table and create a procedure to compare with future database statistics
  • E、write the current database metrics to a database table and submit a job using DBMS_JOB to compare with future database statistics

正确答案:A

第8题:

In your multitenant container database (CDB) containing pluggable database (PDBs), you granted theCREATE TABLE privilege to the common user C A_ADMIN in root and all PDBs. You execute thefollowing command from the root container:SQL >REVOKE create table FROM C A_ADMIN;What is the result?()

A. It executes successfully and the CREATE TABLE privilege is revoked from C # # A_ADMIN in root only.

B. It fails and reports an error because the CONTAINER=ALL clause is not used.

C. It excludes successfully and the CREATE TABLE privilege is revoked from C # # A_ADMIN in root and all PDBs.

D. It fails and reports an error because the CONTAINER=CURRENT clause is not used.

E.It executes successfully and the CREATE TABLE privilege is revoked from C # # A_ADMIN in all PDBs.


参考答案:A

第9题:

In which scenario do you use the Flashback Database feature?()

  • A、 when a table is dropped and you restore it from the Recycle Bin
  • B、 when a user’s schema is dropped and you recover the user’s schema
  • C、 when some incorrect data is inserted in the table and you retrieve the table to a state that was at a certain timestamp
  • D、 when a row of a table is updated frequently and committed, and you view all the versions of the row within a specific duration

正确答案:B

第10题:

In one of your online transaction processing (OLTP) applications, users are manipulating and querying a database table simultaneously. From the Segment Advisor, you find that one of the tables is highly fragmented and you want to shrink the table immediately without affecting the currently active queries. Which option would you use with the ALTER TABLE command to achieve this objective?()

  • A、 REBUILD
  • B、 CASCADE
  • C、 TRUNCATE
  • D、 ROW MOVEMENT
  • E、 SHRINK SPACE COMPACT
  • F、 SHRINK SPACE CASCADE

正确答案:E

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