.png "TCS Technical Interview Questions")
TCS Technical Interview Questions
11) Explain about Joins, Views, Normalization,
Triggers?
The JOIN keyword is used in an SQL statement to query data from
two or more tables, based on a relationship between specific columns in these
tables.
Tables in a database are often related to each other with keys.
A view is a virtual table. A look contains rows and columns, just
like a real table. The fields in a picture are fields from one or more real
tables in the database.
You can add SQL functions, WHERE, and JOIN statements to a view
and present the data as if the data were coming from one single table.
12) List different advantages of DBMS
Improved data sharing.
The list of several advantages of DataBase Management System:
- Improved
data security.
- Better
data integration.
- Minimized
data inconsistency.
- Improved
data access.
- Improved
decision making.
- Increased
end-user productivity.
13) What is Database Management System?
A DataBase Management System is a software system used for
creating and managing databases. DBMS make it possible for the end user to
build and maintain databases. DBMS provides an interface between the end
user/application and the databases.
14) What is database Schema?
The formal definition of the database schema is a set of formulas
(sentences) called integrity constraints imposed on a database.
15) What are the conditional statements?
The conditional statements can alternatively be called as
conditional expression also. Conditional comments are the set of rules which
were executed if a particular condition is true. It is often referred to an
if-then statement because if the state is true, then the statement is executed.
16) What is the difference between the foreign
key and reference key?
Reference Key is the primary key that is referenced in the other
table (linked via the other tables Foreign Key). Foreign Key is how you connect
the second table to the primary tables Primary Key (or Reference Key).
17) What is the difference and similarity
between C and C++?
C++ has classes whereas C did not have classes.
C does not support function overloading. In C, for input or
output, we use functions like gets(), puts(), scanf(), printf(), etc
C does not support exception handling.
18) The structural difference between bitmap
and b-tree index?
Btree
It is made of branch nodes and leaf nodes. Branch nodes hold
prefix key value along with the link to the leaf node and the leaf nodes
contain the indexed value and rowed.
Bitmap
It consists merely of bits for every single distinct value. It
uses a string of bits to locate rows in a table quickly. It is used to index
low cardinality columns.
19) What is the difference between a Clustered
index and non-clustered index?
Clustered Index
- Only one
per table
- Faster to
read than non clustered as data is physically stored in index order
Non-Clustered Index
- Can be
used lot of times per table
- Quicker
for insert and update operations than a clustered index
20) Diffrentiate between socket and session?
Socket is the Combination of IP address and Port Number (in pairs)
The session is a Logical Connectivity between the source and
destination.