A senior DBA asked you to execute the following command to improve performance:
SQL> ALTER TABLE subscribe log STORAGE (BUFFER_POOL recycle);
You checked the data in the SUBSCRIBE_LOG table and found that it is a large table containing
one million rows.
What could be a reason for this recommendation?
A.
The keep pool is not configured.
B.
Automatic Workarea Management is not configured.
C.
Automatic Shared Memory Management is not enabled.
D.
The data blocks in the SUBSCRIBE_LOG table are rarely accessed.
E.
All the queries on the SUBSCRIBE_LOG table are rewritten to a materialized view.
Explanation:
The most of the rows in SUBSCRIBE_LOG table are accessed once a week.
Answer is D only
Configuring the RECYCLE Pool
You can configure a RECYCLE buffer pool for blocks belonging to those segments that you do not want to keep in memory. The purpose of the RECYCLE pool is to retain segments that are scanned rarely or are not referenced frequently. If an application randomly accesses the blocks of a very large object, then it is unlikely for a block stored in the buffer pool to be reused before it is aged out. This is true regardless of the size of the buffer pool (given the constraint of the amount of available physical memory). Consequently, the object’s blocks do not need to be cached; the cache buffers can be allocated to other objects.
D – TRUE
You can configure a RECYCLE buffer pool for blocks belonging to those segments that you do not want to keep in memory. The purpose of the RECYCLE pool is to retain segments that are scanned rarely or are not referenced frequently
http://docs.oracle.com/database/121/TGDBA/tune_buffer_cache.htm#TGDBA552
D
D