Telephonic Interview for DBA

H : How many years experience do you have in DBA ?
P : It is about 2.5 years.
 
H : What was your job as DBA ?
P : Installation of Oracle, creating logical structures, database design, formulating backup and
recovery procedure, maintaining database security by defining roles and privileges and performance tuning.

H : What is the purpose of using SQL*Net ?
P : SQL*Net is required to connect client and server in the C/S architecture. It is also used to configure multi-threaded architecture.

H : What is the use of having multi-threaded architecture ?
P : Multi-threaded architecture basically reduces the number of servers accessing ORACLE database. As one server can handle the requests of many users, number of processes accessing the database will be greatly reduced. In this way, it contributes to the over all system performance.

H : What is SGA ?
P : System Global area is a memory structure used to act as an interface for accessing the Oracle database. It contains shared pool (Library cache & Data dictionary cache), Database buffer cache, redo log buffer. It also caches rollback segment. Private SQL area is also a part of shared pool if it is a multi-threaded architecture.

H : What is the tool that used for monitoring hardware I/O ?
P : I didn’t use any such tool.

H :  Have you implemented Distributed data processing system?
P : I didn’t get a chance to work on Distributed data processing system, I know how to configure Distributed databases and network access methodologies.
 
H : What is striped table ?
P : Striped table is one whose data is spread among more than one disks to improve access performance.

H : What are the disadvantages with striped table ?
P : If one of the disk holding table data crashes, the table cannot be accessed.

H : Have you used striped tables in your application ? Tell me other disadvantages.
P : There was no requirement for using striped tables in my application.  I have no idea about other disadvantages.

H : What is the functionality of LGWR ?
P : This background process is used to copy the data from log buffer to redo log file. If CKPT is not present, it does the work of CKPT process, ie., it updates the headers of datafiles, controlfiles with the latest SCN (system change number).

H : Ok. Bye.
P : Bye bye.