OCA OCP Oracle Certification Exam Braindumps

61. You executed a series of UPDATE statements on one of the tables. This resulted in row migration in the table.
You want to eliminate row migration. Which action on the table would eliminate row migration? (Choose all that apply.)
A.export, drop and importing the table
B.executing the ALTER TABLE..MOVE command on the table
C.allocating an extent to the table by using the ALTER TABLE command
D.executing the ALTER TABLE..DEALLOCATE UNUSED command on the table
 
ANSWER: AB
 
62. You notice that large number of rows are migrated in one of the production tables. Which configuration could have caused this problem?
A.The default block size is very small.
B.PCTFREE is set to a very low value.
C.PCTUSED is set to a very high value.
D.The segment space management is set to AUTO.
E.The table is stored in a locally managed tablespace.
 
ANSWER: B
 

63. When a row in a table is chained or migrated, performance associated with that row degrades. What are the two reasons for this? (Choose two.)
A.because the ROWID for migrated rows have changed
B.because all the existing indexes on the table have become invalid
C.because Oracle must scan more than one data block to retrieve the information for migrated rows
D.because additional I/Os are performed when SELECT statements use an index to select migrated or chained rows
 
ANSWER: CD
 

64. You have the following outcome from the V$SYSSTAT view: What action would you take to have control of this value in the future?
A.increase the NEXT setting for the tables with row migration problems
B.increase the PCTUSED setting on the tables with row migration problems
C.increase the PCTFREE setting on the tables with row migration problems
D.increase the MAXEXTENTS setting on the tables with row migration problems
 
ANSWER: C
 

65. Which two statements are valid regarding row migration? (Choose two.)
A.It can be reduced by decreasing the PCTFREE value.
B.The row migration causes more than one block to be read when a row is accessed.
C.It can be resolved by using the ANALYZE TABLE...ESTIMATE STATISTICS command.
D.It is caused by inserting a row into an empty data block where the row is too large to fit into that empty block.
E.It is caused by an UPDATE statement that increases the data in a row so that the new larger version of the row no longer fits in its data block.

ANSWER: BE