REDOLOG FILES & CONTROL FILES INTERVIEW QUESTIONS
Why to multiplex redolog files?
- To avoid any data loss
What is log switch?
- LGWR switching between two redolog groups
3.If we have multiple members in a single group, how LGWR will write into them?
It will write paralley if ASYNC I/O is enabled at OS level. Otherwise, it will write insequential order
Can we have different sizes for members in the same group?
Can we create different groups with different sizes?
Yes. But it is not recommended as checkpoint occurence will change and it will not be consistent
What is the use of FAST_START_MTTR_TARGET parameter?
It is used to specify at what frequency checkpoint should occur in order to make data permanent
What is the min size that can be given during redolog file creation?
How to resize the redolog files?
Not possible. If we want, we can create new group with more size and drop existing group
Where to check the status of redolog group? What it mean when we see INVALID status?
We can check from v$log view and INVALID means redolog file or group is corrupted
- Where we can check controlfile location?
Using CONTROL_FILES parameter
- What is archive log mode? Why it is required?
Archive log mode is a modein which database stores all the changes occured in the form of archives. It is used to recover the database when we have old backup
What is the default location of archives in 10g?
Flash recovery area
If archive destination is full, how you will react?
- We will first see for possibility of taking backup, if not we will move some archives to other mount point or in worst case we will delete them. But when we delete them, immediately we need to take full database back