Oracle Basic Questions

Explain oracle architecture?

What is normalization? what is the advantage of normalization?
Normalization is the process of removing redundant data from your tables

What are the types of SQL Statement ?
DDL - Create, Alter..
DML - Insert, Update ..

What is a join ? Explain the different types of joins ?

Self Join - Joining the table with itself.

Equi Join - Joining two tables by equating two common columns.
Non-Equi Join - Joining two tables by equating two common columns.
Outer Join - Joining two tables in such a way that query can also retrive rows that do not have corresponding join value in the other table.

What is difference between TRUNCATE & DELETE ?

Truncate is a DDL Statement, cannot rollback
Delete is a DML statement, can issue rollback

What is difference between group functions and single row functions?

What is difference between DECODE and TRANSLATE ?

What is difference between SUBSTR and INSTR

Bitmap and B-tree index?

What is a view ? What are materialized views (snapshots)?

Significance of keys ? primary key , unique key?