Immediately after adding a new disk to or removing an existing disk from an ASM instance, you find that the performance of the database goes down initially until the time the addition or removal process is completed, and then gradually becomes normal.
Which two activities would you perform to maintain a consistent performance of the database while adding or removing disks?（）

You are working on a 24X7 database. You want to design a backup strategy for your database that uses user managed backups. You want to be able to perform all backups while the database remains online.
Which statement about performing user-managed backups in a 24x7 environment is true?（）

A new report process containing a complex query is written, with high impact on the database. You wantto collect basic statistics about query, such as the level of parallelism, total database time, and the number of I/O requests.
For the database instance STATISTICS_LEVEL, the initialization parameter is set to TYPICAL and theCONTROL_MANAGEMENT_PACK_ACCESS parameter is set to DIAGNOSTIC+TUNING.
What should you do to accomplish this task?（）

You are developing a Windows Communication Foundation (WCF) service that is hosted by a Windows Forms Application.The ServiceHost instance is created in the Form Constructor.You need to ensure that the service is not blocked while the UI thread is busy.
What should you do?（）

You have a DHCP server that runs Windows Server 2008 R2.You need to reduce the size of the DHCP database.
What should you do？（）