DataBase Administrator (DBA) Interview Questions and Answers
(Continued from previous part...)
194. Name two files used for network connection to a database.
TNSNAMES.ORA and SQLNET.ORA
195. What?s the command to see the current user name?
Sql> show user;
196. How do you switch to DOS prompt from SQL prompt?
197. What are the basic element of Base configuration of an oracle Database?
It consists of one or more data files. one or more control files. two or more redo log files. The Database contains multiple users/schemas one or more rollback segments one or more tablespaces Data dictionary tables User objects (table, indexes, views etc.,) The server that access the database consists of SGA (Database buffer, Dictionary Cache Buffers, Redo log buffers, Shared SQL pool) SMON (System MONito) PMON (Process MONitor) LGWR (LoG Write) DBWR (Data Base Write) ARCH (ARCHiver) CKPT (Check Point) RECO Dispatcher User Process with associated PGS
198. What is clusters?
Group of tables physically stored together because they share common columns and are often used together is called Cluster.
199. What is an Index? - How it is implemented in Oracle Database?
An index is a database structure used by the server to have direct access of a row in a table. An index is automatically created when a unique of primary key constraint clause is specified in create table command (Ver 7.0)
200. What is a Database instance?
Explain A database instance (Server) is a set of memory structure and background processes that access a set of database files. The process can be shared by all users. The memory structure that are used to store most queried data from database. This helps up to improve database performance by decreasing the amount of I/O performed against data file.
201. What is the use of ANALYZE command?
To perform one of these function on an index, table, or cluster: - To collect statistics about object used by the optimizer and store them in the data dictionary. - To delete statistics about the object used by object from the data dictionary. - To validate the structure of the object.. - To identify migrated and chained rows off the table or cluster.
202. What is default tablespace?
The Tablespace to contain schema objects created without specifying a tablespace name.
203. What are the system resources that can be controlled through Profile?
The number of concurrent sessions the user can establish the CPU processing time available to the userís session the CPU processing time available to a single call to ORACLE made by a SQL statement the amount of logical I/O available to the userís session the amount of logical I/O available to a single call to ORACLE made by a SQL statement the allowed amount of idle time for the userís session the allowed amount of connect time for the userís session.
(Continued on next part...)