You are managing an online transaction processing (OLTP) system. Many users complain about
the slow response time. You investigated and found that in the Top 5 events, direct path read
accounts for 73.2% of the total wait time.Which two are the possible reasons for the high direct
path read time? (Choose two.)
A.
The I/O subsystem is slow.
B.
The SQL statements are using high CPU.
C.
The SQL statement has a long parsing time.
D.
The SQL statements are performing a large number of physical and logical reads.
http://docs.oracle.com/cd/B16240_01/doc/doc.102/e16282/oracle_database_help/oracle_database_wait_bottlenecks_direct_path_read_pct.html
Direct path read (%)
Description
The session is waiting for a direct read to complete. A direct read is a physical I/O from a data file that bypasses the buffer cache and reads the data block directly into process-private memory.
High direct path read: 1. slow disk, 2. large physical/logical read
So A. D.