Examine the structure of the sales table, which is stored in a locally managed tablespace with
Automatic Segment Space Management (ASSM) enabled.
NameNull?Type
——————————————– ————————————- —————————–PROD_IDNOT NULL NUMBER
CUST_IDNOT NULL NUMBER
TIME_IDNOT NULL DATE
CHANNEL_IDNOT NULL NUMBER
PROMO_IDNOT NULL NUMBER
QUANT I TY___S OL DNOT NULL NUMBER (10, 2) AMOUNT SOLDNOT NULL NUMBER (10,
2)
You want to perform online segment shrink to reclaim fragmented free space below the high water
mark.
What should you ensure before the start of the operation?
A.
Row movement is enabled.
B.
Referential integrity constraints for the table are disabled.
C.
No queries are running on this table.
D.
Extra disk space equivalent to the size of the segment is available in the tablespace.
E.
No pending transaction exists on the table.
Explanation:
Refer – http://docs.oracle.com/cd/E18283_01/server.112/e17120/schema003.htm#CBBBIADA, Shrinking Database Segments Online
The correct answer will be enable row movement.
Segment shrink requires that rows be moved to new locations. Therefore, you must first enable row movement in the object you want to shrink and disable any rowid-based triggers defined on the object. You enable row movement in a table with the ALTER TABLE … ENABLE ROW MOVEMENT command.
Segment shrink is an online, in-place operation. DML operations and queries can be issued during the data movement phase of segment shrink. Concurrent DML operations are blocked for a short time at the end of the shrink operation, when the space is deallocated. Indexes are maintained during the shrink operation and remain usable after the operation is complete. Segment shrink does not require extra disk space to be allocated.
Reference for 12c : http://docs.oracle.com/database/121/ADMIN/schema.htm#ADMIN10161
Correct should be: A
A and A and only A
A
A is correct because:
– DML operations and queries can be issued during the data movement phase of segment shrink
– Segment shrink does not require extra disk space to be allocated
– Segment shrink requires that rows be moved to new locations. Therefore, you must first enable row movement in the object you want to shrink and disable any rowid-based triggers defined on the object. You enable row movement in a table with the ALTER TABLE … ENABLE ROW MOVEMENT command.
http://docs.oracle.com/database/121/ADMIN/schema.htm#ADMIN10161
A
A
A
A is only correct