For which two systems would you recommend configuring DBWR I/O slaves instead of multiple
database writer processes? (Choose two.)
A.
for systems where you have a single CPU
B.
for systems where asynchronous I/O is not available
C.
for systems with multiple CPUs or multiple processor groups
D.
for systems where asynchronous I/O is available and configured
E.
for systems where throughput is an important performance consideration
A and B
You can’t activate both multiple DBWRs and I/O slaves. If both parameters are activated, DBWR_IO_SLAVES will take precedence. To determine whether to use multiple DBWn processes or database slaves, follow these guidelines:
For write intensive applications that also have a large data buffer cache (100,000 and up), configure DB_WRITER_PROCESSES
For applications that are not write intensive and run on operating systems that support asynchronous I/O, configure DBWR_IO_SLAVES
If the operating system does not support asnychronous I/O, use DBWR_IO_SLAVES
If your server only has one CPU, use DBWR_IO_SLAVES, DBWR processes are CPU intensive
A is right. with single cpu, db_writer_processes is 1 where dbwr_io_slaves become relevant
B is right. dbwr_io_slaves is to simulate async IO
So A.B. are correct