45.What is the advantage of setting the ASM-preferred mirror read for the Stretch cluster configuration?
A. It improves resync operations.
B. This feature enables much faster file opens.
C. It improves performance as fewer extent pointers are needed in the shared pool.
D. It improves performance by reading from a copy of an extent closest to the node.
Answer: D
答案解析：
Oracle ASM Preferred Read Disk Groups
In previous releases, Oracle ASM used the disk with the primary copy of a mirrored extent as the preferred disk for data read operations. With this release, using the new initialization file parameter asm_preferred_read_failure_groups,
you can specify disks located near a specific cluster node as the preferred disks from which that node obtains mirrored data. This option is presented in DBCA, or you can configure it after installation. This change facilitates
faster processing of data with widely distributed shared storage systems or with extended clusters (clusters whose nodes are geographically dispersed), and improves disaster recovery preparedness.