| 1: | Which statement about an Oracle instance is true? A. The data dictionary cache is not part of the shared memory area of an Oracle instance. B. Multiple instances and therefore multiple databases can execute on the same computer. C. The Oracle Server is a combination of memory structures, background processes, and external files. D. Database writer writes the redo logs from the redo log buffer to the redo log files.
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| A1: | Answer B is correct. It is possible, and often the case, to have multiple instances running on a single computer, each accessing its own physical database. Answer A is incorrect because the data dictionary cache is part of the shared memory area, or the SGA, of an Oracle instance. Answer C is incorrect because an Oracle Server is the combination of the Oracle database and the Oracle instance. Answer D is incorrect because database writer writes the dirty data buffers out to the datafiles and log writer writes the redo logs from the redo log buffer to the redo log files. |
| 2: | Which of the following is responsible for writing data blocks from the database buffer cache out to the datafiles? A. DBWn B. RECO C. ARCn D. Jnnn
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| A2: | Answer A is correct. Database Writer is responsible for writing data from the database buffer cache out to the datafiles. Answer B is incorrect because Recoverer is responsible for resolving transactions left pending due to a network or system failure. Answer C is incorrect because Archiver writes the active redo log files to archive log files when there is a log switch. Answer D is incorrect because the job queue process assists with automating batch job processes. |
| 3: | Which tablespace is the minimum required when creating a new database? A. Undo tablespace B. Temporary tablespace C. System tablespace D. Users tablespace
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| A3: | Answer C is correct; the minimum necessary tablespace for the creation of a database is the system tablespace. Answer A is incorrect because, although an undo tablespace is necessary for implementation of automatic undo, it is not necessary for the creation of the database. Answer B is incorrect because although a temporary tablespace is a good idea at creation time and for use by users, it is not necessary for creation. Answer D is incorrect because a user's tablespace isn't necessary. |
| 4: | Which three types of files are parts of an Oracle database? [Choose three] A. Control file B. Archive log file C. Redo log files D. Parameter files E. Datafiles
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| A4: | Answers A, C, and E are correct. Control files hold entries that specify the physical structure of the database, redo log files hold a record of all changes made to any data in the database, and datafiles hold the user data stored in the database. Answer B is incorrect because the Archive log files are used in backup and recovery and are written to by log writer when there is a log switch, but they are external files to the database. Answer D is incorrect because parameter files hold information that Oracle uses when it starts up, but they are not considered a part of the database. |
| 5: | From smallest to largest, rank the following logical pieces of the database: data block, tablespace, extent, segment. A. Tablespace, segment, extent, data block B. Data block, segment, extent, tablespace C. Segment, extent, data block, tablespace D. Data block, extent, segment, tablespace
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| A5: | Answer D is correct: data blocks make up extents; extents make up segments; and segments make up tablespaces. Answer A is incorrect because it is from largest to smallest. Answer B is incorrect because segments don't make up extents. Answer C is largest to smallest except for tablespace, which is in the wrong place. |
| 6: | Which two statements about storage structures in the Oracle database are true? [Choose two] A. A data block is a logical structure. B. One file can belong to more than one tablespace. C. An extent can belong to more than one tablespace. D. A tablespace can contain more than one datafile. E. A data block can belong to multiple datafiles. F. An extent can be made up of more than one segment.
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| A6: | Correct answers are A and D. A data block is a logical structure, and a tablespace is often made up of more than one datafile. Answer B is incorrect because a datafile can belong to only one tablespace. Answer C is incorrect because an extent can be a part of only one tablespace. Answer E is incorrect because, although a data block can be multiple operating system blocks, they must all belong to the same datafile. Answer F is incorrect because segments are made up of extents (one or many), but extents are not made up of segments. |
| 7: | When is the SGA created in an Oracle instance? A. the database is created. B. When the instance is opened. C. When the user process is started. D. When a server process is started.
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| A7: | Answer B is correct. The SGA, as part of the memory structure, is created when the instance is started and remains allocated until the instance is shut down. Answer A is incorrect because the SGA isn't part of the database. Answer C in incorrect because user processes have to interact with an open instance, and the SGA, as a memory structure, opens when the instance opens. Answer D is incorrect, because, as a memory structure, the SGA has to be available before any server processes can start. |
| 8: | When is the PGA created in an Oracle instance? A. When the instance is created. B. When the database is mounted. C. When a single user logs directly into the database. D. When a server process is started.
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| A8: | Answer D is correct. The PGA gets created to support a server process and, therefore, gets created when that server process is started. Answer A is incorrect because if no server processes are running, the PGA is not necessary. Answer B is incorrect because when the database is mounted no server processes are available to start the PGA. Answer C is incorrect because the PGA supports server processes, not user processes. |
| 9: | Which statement is true about segments? A. Each table has its own segment. B. A segment is created every time an extent is created, extended, or altered. C. An index segment is created every time a table is created. D. A segment is deleted whenever a table is truncated.
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| A9: | Answer A is correct. Each table, index, or other database object has its own segment. Answer B is incorrect because a segment is made up of multiple extents. Answer C is incorrect because index segments are created for indexes, and table segments are created for tables. Answer D in incorrect because the only time a segment is deleted is when the object that they are created on is dropped or truncated with either the REUSE STORAGE or DROP STORAGE parameters included. |
| 10: | At what point does the CKPT process write data blocks to the datafiles? [Select all that apply] A. Whenever LOG_CHECKPOINT_INTERVAL parameter tells it to. B. Whenever LOG_CHECKPOINT_TIMEOUT tells it to. C. Whenever there is a log switch. D. CKPT doesn't write anything out to files; it tells the other processes to do that.
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| A10: | Answer D is the only correct answer. Checkpoint doesn't actually write anything out to files; it causes the DBWn process to write the data from the database buffer cache out to the database files. Answer A is incorrect because LOG_CHECKPOINT_INTERVAL tells CKPT how often in terms of volume to cause a checkpoint, but it does not ever write anything. Answer B is incorrect because LOG_CHECKPOINT_TIMEOUT tells CKPT how often in terms of periods of time in seconds to cause a checkpoint, but it does not ever write anything. Answer C is incorrect because a log switch causes CKPT to occur, but it does not ever write anything. |
