Questão 1
Questão
1. One of the main functions of a database system is to provide timely answers to end users.
Questão 2
Questão
2. Good database performance is easy to evaluate
Questão 3
Questão
3. All factors must be checked to ensure that each system component operates at its optimum level and has sufficient resources to minimize the occurrence of bottlenecks.
Questão 4
Questão
4. Good database performance starts with good database design.
Questão 5
Questão
5. DBMS implementations are typically similar in complexity to two-tier client/server configurations.
Questão 6
Questão
6. A data file can contain rows from a single table alone.
Questão 7
Questão
7. The data cache caches system catalog data and the contents of the indexes.
Questão 8
Questão
8. The SQL cache stores the end-user written SQL.
Questão 9
Questão
9. To work with data, the DBMS must retrieve the data from permanent storage and place it in RAM.
Questão 10
Questão
10. The purpose of an I/O operation is to move data to and from different computer components or devices.
Questão 11
Questão
11. Working with data in the data cache is many times faster than working with data in the data files.
Questão 12
Questão
12. Fully equivalent means that the optimized query results are always the same as the original query.
Questão 13
Questão
13. The SQL execution activities are performed by the query optimizer.
Questão 14
Questão
14. All transaction management commands are processed during the parsing and execution phases of query processing.
Questão 15
Questão
15. An index scan is less efficient than a full table scan.
Questão 16
Questão
16. Indexes do not facilitate join operations.
Questão 17
Questão
17. Using index characteristics, a database designer can determine the best type of index to use.
Questão 18
Questão
18. A cost-based optimizer uses a set of preset rules and points to determine the best approach to execute a query.
Questão 19
Questão
19. The primary factor in determining the most efficient access plan is the I/O cost.
Questão 20
Questão
20. Most current-generation relational DBMSs perform automatic query optimization at the client end.
Questão 21
Questão
21. Indexes are very useful in small tables or tables with low sparsity.
Questão 22
Questão
22. Character field comparisons are faster than numeric, date, and NULL comparisons
Questão 23
Questão
23. In-memory database systems are optimized to store small portions of the database in disk storage alone
Questão 24
Questão
24. DBMS performance tuning includes global tasks such as managing the DBMS processes in primary memory and managing the structures in physical storage.
Questão 25
Questão
25. Maximizing disk contention is one of the general recommendations for the physical storage of databases.
Questão 26
Questão
26. RAID systems use a single disk to create storage volumes.
Questão 27
Questão
27. On the client side, the objective is to generate an SQL query that returns a correct answer in the least amount of time, using a minimum amount of resources at the server end. The activities required to achieve this goal are commonly referred to as tuning.
Responda
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a. client SQL
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b. database SQL
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c. SQL performance
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d. DBMS performance
Questão 28
Questão
28. On the server side, the database environment must be properly configured to respond to clients' requests in the fastest way possible, while making optimum use of existing resources. The activities required to achieve this goal are commonly referred to as tuning.
Responda
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a. client and server
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b. database SQL
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c. SQL performance
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d. DBMS performance
Questão 29
Questão
29. When moving data from permanent storage to RAM, an I/O disk operation retrieves:
Responda
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a. an entire table.
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b. an entire physical disk block.
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c. only the row containing the attribute requested.
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d. only the attribute which was requested.
Questão 30
Questão
30. A DBA determines the initial size of the data files that make up the database; however, as required, the data files can automatically expand in predefined increments known as .
Responda
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a. procedure cache
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b. buffer cache
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c. supplements
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d. extends
Questão 31
Questão
31. A(n) is a logical grouping of several data files that store data with similar characteristics.
Responda
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a. procedure cache
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b. table space
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c. data cache
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d. listener
Questão 32
Questão
32. A system table space, a user data table space, an index table space, and a temporary table space are examples of _____.
Responda
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a. procedure caches
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b. file groups
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c. data caches
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d. operation modes
Questão 33
Questão
33. The data cache is where the data read from the database data files are stored the data have been read or the data are written to the database data files.
Responda
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a. after; before
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b. after; after
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c. before; before
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d. before; after
Questão 34
Questão
34. To work with data, a DBMS must retrieve the data from and place them in .
Responda
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a. data files; procedure cache
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b. RAM; data cache
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c. permanent storage; RAM
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d. temporary files; procedure cache
Questão 35
Questão
35. The data cache or is a shared, reserved memory area that stores the most recently accessed data blocks in RAM.
Responda
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a. buffer cache
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b. procedure cache
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c. SQL cache
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d. permanent storage
Questão 36
Questão
36. The is a shared, reserved memory area that stores the most recently executed SQL statements or PL/SQL procedures, including triggers and functions.
Responda
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a. buffer cache
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b. procedure cache
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c. data cache
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d. permanent storage
Questão 37
Questão
37. The process analyzes SQL queries and finds the most efficient way to access data.
Responda
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a. optimizer
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b. scheduler
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c. listener
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d. user
Questão 38
Questão
38. To generate database object statistics manually, following syntax should be used in Oracle: .
Responda
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a. ANALYZE <TABLE/INDEX> object_name;
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b. CREATE <TABLE/INDEX> object_name;
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c. ANALYZE <TABLE/INDEX> object_name COMPUTE STATISTICS;
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d. CREATE <TABLE/INDEX> object_name COMPUTE STATISTICS;
Questão 39
Questão
39. Automatic query optimization means that the:
Responda
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a. optimization takes place at compilation time by the programmer.
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b. DBMS finds the most cost-effective access path without user intervention.
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c. optimization process is scheduled and selected by the end user or programmer.
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d. database access strategy is defined when the program is executed.
Questão 40
Questão
40. The DBMS the SQL query and chooses the most efficient access/execution plan.
Responda
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a. parses
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b. executes
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c. fetches
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d. processes
Questão 41
Questão
41. Which of the following is the first step of query processing at the DBMS server end?
Responda
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a. Executing
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b. Parsing
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c. Fetching
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d. Delivering
Questão 42
Questão
42. The DBMS the data and sends the result set back to the client.
Responda
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a. parses
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b. executes
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c. fetches
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d. processes
Questão 43
Questão
43. If there is no index, the DBMS will perform a scan.
Responda
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a. loop
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b. range
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c. row ID table access
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d. full table
Questão 44
Questão
44. refers to the number of different values a column could possibly have.
Responda
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a. Database statistics
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b. Data sparsity
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c. A bitmap index
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d. Clustering
Questão 45
Questão
45. Bitmap indexes tend to use less space than a because they use bits instead of bytes to store their data.
Responda
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a. hash index
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b. sparse index
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c. B-tree index
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d. reverse index
Questão 46
Questão
46. Knowing the sparsity of a column helps you decide whether the use of is appropriate.
Responda
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a. query processing
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b. query optimization
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c. an index
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d. a full table scan
Questão 47
Questão
47. is the central activity during the parsing phase in query processing.
Responda
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a. Clustering
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b. Partitioning
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c. Query validation
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d. Query optimization
Questão 48
Questão
48. When setting optimizer hints, instructs the optimizer to minimize the overall execution time, that is, to minimize the time it takes to return the total number of rows in the query result set. This hint is generally used for batch mode processes.
Responda
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a. ALL_ROWS
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b. FIRST_ROWS
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c. INDEX(P_QOH_NDX)
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d. OPTIMIZATION_ROWS
Questão 49
Questão
49. In standard SQL, the optimizer hint FIRST_ROWS is generally used for mode processes.
Responda
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a. batch
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b. interactive
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c. transaction
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d. real-time
Questão 50
Questão
50. In standard SQL, the optimizer hint ALL_ROWS is generally used for mode processes.
Responda
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a. interactive
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b. real-time
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c. batch
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d. transaction
Questão 51
Questão
51. The LIKE conditional operator is used by the OPERAND1.
Responda
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a. P_PRICE
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b. V_STATE
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c. P_QOH
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d. V_CONTACT
Questão 52
Questão
52. The must be set large enough to permit as many data requests to be serviced from cache as possible.
Responda
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a. data cache
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b. SQL cache
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c. sort cache
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d. optimizer mode
Questão 53
Questão
53. The majority of primary memory resources will be allocated to the cache.
Responda
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a. data
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b. SQL
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c. sort
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d. optimizer
Questão 54
Questão
54. The cache is used as a temporary storage area for ORDER BY or GROUP BY operations, as well as for index-creation functions.
Responda
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a. data
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b. SQL
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c. sort
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d. optimizer
Questão 55
Questão
55. From the performance point of view, databases eliminate disk access bottlenecks.
Responda
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a. RAID
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b. distributed
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c. index-organized
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d. in-memory
Questão 56
Questão
56. The table space is used for transaction-recovery purposes.
Responda
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a. system
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b. user data
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c. temporary
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d. rollback segment
Questão 57
Questão
57. In the context of RAID levels, refers to writing the same data blocks to separate drives.
Responda
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a. striping
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b. mirroring
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c. partitioning
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d. aggregating
Questão 58
Questão
58. The table space is used to store the data dictionary tables.
Responda
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a. system
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b. user data
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c. temporary
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d. rollback segment
Questão 59
Questão
59. In the context of RAID levels, striped arrays provide:
Responda
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a. increased read performance and fault tolerance.
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b. increased fault tolerance but decreased performance.
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c. increased read performance but no fault tolerance
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d. neither fault tolerance nor good performance.
Questão 60
Questão
60. In RAID level 5,:
Responda
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a. the data and the parity data are striped across separate drives.
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b. the data blocks are spread over separate drives and are duplicated.
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c. the array requires a minimum of two drives and is known as a striped array.
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d. the array requires a minimum of five drives and is known as duplexing.