OCM OCM Database Administration & SQL

Question 1

Which Oracle feature allows you to recover a dropped table without restoring from a backup?

Accepted Answer

Flashback Table

Answer

LogMiner

Answer

RMAN Block Recovery

Answer

Data Guard Redo Apply

Question 2

What is the purpose of the UNDO tablespace in Oracle Database?

Accepted Answer

Providing read consistency and supporting transaction rollback

Answer

Storing archived redo logs

Answer

Holding temporary sort segments

Answer

Caching frequently accessed index blocks

Question 3

Which SQL hint forces the Oracle optimizer to use a full table scan instead of an index?

Accepted Answer

/*+ FULL(table) */

Answer

/*+ INDEX(table) */

Answer

/*+ NO_MERGE */

Answer

/*+ PARALLEL */

Question 4

In Oracle, what does the PCTFREE storage parameter control?

Accepted Answer

Percentage of block space reserved for future row updates

Answer

Minimum percentage of a block that must be full before rows are added

Answer

Number of free lists for concurrent inserts

Answer

Maximum percentage of extents that can be free

Question 5

Which Oracle background process is responsible for writing dirty buffers from the buffer cache to datafiles?

Accepted Answer

DBWR

Answer

LGWR

Answer

SMON

Answer

CKPT

Question 6

What is the effect of setting the OPTIMIZER_MODE parameter to FIRST_ROWS_10?

Accepted Answer

Optimizer chooses plans that return the first 10 rows as fast as possible

Answer

Optimizer minimizes total resource consumption for all rows

Answer

Optimizer limits result sets to 10 rows

Answer

Optimizer uses 10 parallel threads for query execution