SQL Server Job Interview Questions part 5

Que:- What are the properties of the Relational tables?Ans:- Relational tables have six properties:• Values are atomic.• Column values are of the same kind.• Each row is unique.• The sequence of columns is insignificant.• The sequence of rows is insignificant.• Each column must have a unique name.Que:- What is De-normalization?Ans:- De-normalization is the process of attempting to optimize the performance of a database by adding redundant data. It is sometimes necessary because current DBMSs implement the relational model poorly. A true relational...

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SQL Server Job Interview Questions part 4

Que:- What is User Defined Functions?Ans:- User-Defined Functions allow to define its own T-SQL functions that can accept 0 or more parameters and return a single scalar data value or a table data type.Que:- What kind of User-Defined Functions can be created?Ans:- There are three types of User-Defined functions in SQL Server 2000 and they are Scalar, Inline Table-Valued and Multi-statement Table-valued.Scalar User-Defined FunctionA Scalar user-defined function returns one of the scalar data types. Text, ntext, image and timestamp data types are...

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SQL Server Job Interview questions part 3

Que:- What is a NOLOCK? Ans:- Using the NOLOCK query optimiser hint is generally considered good practice in order to improve concurrency on a busy system. When the NOLOCK hint is included in a SELECT statement, no locks are taken when data is read. The result is a Dirty Read, which means that another process could be updating the data at the exact time you are reading it. There are no guarantees that your query will retrieve the most recent data. The advantage to performance is that your reading of data will not blockupdates from taking place,...

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SQL Server Interview questions - part 2

Que:- What is Index?Ans:- An index is a physical structure containing pointers to the data. Indices are created in an existing table to locate rows more quickly and efficiently. It is possible to create an index on one or more columns of a table, and each index is given a name. The users cannot see the indexes, they are just used to speedup queries. Effective indexes are one of the best ways to improve performance in a database application. A table scan happens when there is no index available to help a query. In a table scan SQL Server examines...

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SQL Server Interview questions - part 1

SQL Server Interview questions - part 1Que:- What is RDBMS?Ans:- Relational Data Base Management Systems (RDBMS) are database management systems that maintain data records and indices in tables. Relationships may be created and maintained across and among the data and tables. In a relational database, relationships between data items are expressed by means of tables. Interdependencies among these tables are expressed by data values rather than by pointers.This allows a high degree of data independence. An RDBMS has the capability to recombine the...

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