Oracle DBA Interview Questions

DBMS v/s RDBMS

Discuss the advantages and disadvantages of hierarchical database management system in comparison with RDBMS. Discuss types of applications suitable for hierarchical DBMS and RDBMS.

Changes in database buffer cache

What are the changes that happen in database buffer cache(list of all changes in db buffer cache)

Export query

How to write script for export backup in shell.

Instance of database problem

Tell me any instance when your database encountered any problem. How you dealt with that problem.

Properties of database isolation

Describe four properties of database isolation. In which situation lock contention will happen. What is transaction lock?

Simple and advance replication

What is simple replication and advance replication? What is the difference between simple replication and advance replication? How can we do simple replication?

A day as a DBA

How you spend a day as a DBA. Explain DBA activities in detail.

Virtual indexes in Oracle

Virtual indexes are another undocumented feature used by Oracle. Virtual indexes, as the name suggests are pseudo-indexes that will not behave the same way that normal indexes behave, and are meant for a very specific purpose.A virtual index is created in a slightly different manner than the normal indexes....

What is a cluster key ?

 the  related columns of the tables are called the cluster key.  the cluster key  is indexed using a cluster index and its value is stored only once for multiple tables in the cluster.

What are the basic element of base configuration of an Oracle database ?

 it consists ofone or more data files.One or more control files.Two or more redo log files.The database containsmultiple users/schemasone or more rollback segmentsone or more tablespacesdata dictionary tablesuser objects (table,indexes,views etc.,)the server that access the database consists ofsga ...

How materialized views work with object types and collections

This is extract from Oracle10g advanced replication book. How materialized views work with object types and collectionsOracle object types are user-defined datatypes that make it possible to model complex real-world entities such as customers and orders as single entities, called objects, in the database....