Oracle 8-Files, Data & Users

Front 1

When redo logs are used all previously committed transactions will be recovered; this is also known as being? All transactions that had modified data but had not been committed will be backed out; this is known as?

Back 1

rolled forward, rolled back

Front 2

It is recommended that you use which raid level on all redo log files?

Back 2

raid 1

Front 3

A checkpoint causes all in-cache data blocks that have not been written out to disk, to be written out to disk. These unwritten, changed buffers are called?

Back 3

dirty buffers

Front 4

When this operation is performed, the redo information is written into the redo log buffers.

Back 4

commit

Front 5

The redo log is made up of two or more redo log files that oracle automatically mirrors also referred to as?

Back 5

log file group

Hint 5

If you are using disk mirroring to protect the redo log, it is not necessary to use this.

Front 6

when a log file fills up and the log switch occurs, the file is copied to an

Back 6

archive log file

Front 7

A log switch always causes this to occur?

Back 7

checkpoint

Hint 7

flushes all dirty buffers from the Oracle buffer cache

Front 8

Each time a redo log file is reused, it is given a?

Back 8

log sequence number

Hint 8

By having this, the RDBMS can keep track of which log file and archive log files have been used.

Front 9

Select two. Which of the following parameters are used to control the checkpoint interval?

Back 9

LOG_CHECKPOINT_INTERVAL, LOG_CHECKPOINT_TIMEOUT

Front 10

how many blocks are there per 1mb?

Back 10

2048

Front 11

you want to force a checkpoint, you can do it with the following command:

Back 11

alter system checkpoint;

Front 12

As with the checkpoint, a log switch can be forced by hand. To do so, use the following command:

Back 12

alter system switch logfile;

Front 13

Complete the following command to delete the rollback segment log1.

Back 13

ALTER DATABASE orcl drop logfile 'log1';

Front 14

The redo log files are one of the few files in the Oracle database that are always written to in

Back 14

sequential manner

Front 15

It is better to have the archival process and redo log operation on?

Back 15

separate disk volumes

Hint 15

sequential I/O is much faster than random I/O.

Front 16

Using this for the redo log files because it offers the most protection and the fastest write performance.

Back 16

raid 1

Front 17

What is the advantage to isolating redo log files onto separate disk volumes?

Back 17

faster i/o

Front 18

These files are used in the startup of an instance to identify where the datafiles and redo log files are in the system.

Back 18

control files

Front 19

Which of the following commands will generate a new control file?

Back 19

create controlfile

Front 20

Each time you make changes to the structure of the database by adding datafiles, redo log files, and so on, run the command

Back 20

ALTER DATABASE database BACKUP CONTROLFILE TO TRACE;

Front 21

Records transactional information that will be used in the event that the transaction is rolled back.

Back 21

rollback segments

Hint 21

keep the undo information that is used in rollback operations. Provide read consistency and used for database recovery.

Front 22

Which of the following allows a long-running transaction to always obtain the same data within the query?

Back 22

read consistency

Front 23

The information written by the transaction to the rollback segments is held in?

Back 23

rollback entries

Front 24

stores information about which transactions use each rollback segment, and the rollback entries for each change performed by those transactions.

Back 24

transaction table

Front 25

You can manually assign a rollback segment by using the

Back 25

set transaction command with the use rollback segment parameter

Front 26

Where does the system keep the information written by the transaction to the rollback segments?

Back 26

In rollback entries

Front 27

There is a lot of rollback contention even though you are using your space efficiently. What is the problem?

Back 27

Too many transactions sharing a rollback segment

Front 28

A rollback segment must have at least how many extents

Back 28

2

Front 29

When a transaction uses the last extent in the segment, it looks to see whether the first extent is available. If the first extent is not available, what happens?

Back 29

another extent is created

Front 30

With rollback segments, the size for INITIAL should equal this so that all extents are the same size.

Back 30

next

Front 31

Select two. Which of the following CREATE ROLLBACK SEGMENT parameters control the size of the extents?

Back 31

initial and next

Front 32

A good rule of thumb is to create about "x" # of rollback segment for every "y" # of concurrent transactions.

Back 32

x=1, y=4

Hint 32

Remember — the fewer transactions per rollback segment, the less contention

Front 33

Rollback contention occurs when too many transactions try to use the same rollback segment at the same time, and some of them have to wait. You can tell whether you are seeing contention on rollback segments by looking at the dynamic performance table:

Back 33

v$waitstat

Front 34

Typically this rollback segment is not used, and you do not need to be concerned about it in re: to rollback contention.

Back 34

system

Front 35

In the v$sysstat, the number of requests for data is equal to

Back 35

sum of DB BUFFER GETS and CONSISTENT GETS

Front 36

If the number of waits for any of the rollback segment blocks or headers exceeds more than x% of the total number of requests, you should reduce the contention by adding more rollback segments.

Back 36

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