Infosys SQL Database Administrator Interview Questions and Answers

I prefer SQL as it is the language of databases and allows for efficient data management.

• SQL is specifically designed for managing and querying databases

• It allows for efficient data retrieval and manipulation

• Other programming languages can be used in conjunction with SQL for more complex tasks

• Examples of other languages commonly used with SQL include Python and Java

C/C++ are low-level languages, while JAVA is high-level. C/C++ are compiled, while JAVA is interpreted.

• C/C++ are used for system programming and embedded systems.

• JAVA is used for web development and enterprise applications.

• C/C++ have manual memory management, while JAVA has automatic garbage collection.

• C/C++ have pointers, while JAVA does not.

• C/C++ code is platform-dependent, while JAVA code is platform-independent.

• Exa...read more

Synchronization in Java is a process of controlling access to shared resources by multiple threads.

• Synchronization is achieved using synchronized keyword or locks.

• It prevents race conditions and ensures thread safety.

• Example: synchronized methods, synchronized blocks, ReentrantLock.

• Synchronization can cause performance issues if not used properly.

Maps, Hash maps, and Skeleton class are OOPS concepts used in programming.

• Maps are data structures that store key-value pairs.

• Hash maps are a type of map that use a hash function to index the keys.

• Skeleton class is a class that provides a basic implementation of an interface.

• OOPS concepts are Object-Oriented Programming concepts that focus on objects and their interactions.

• Example: HashMap in Java is a commonly used im

A database management system (DBMS) is a software that manages and organizes databases. Primary key uniquely identifies a record, while foreign key establishes a relationship between tables.

• A DBMS is a software that allows users to create, manage, and manipulate databases.

• It provides tools for creating, modifying, and deleting databases, tables, and records.

• Primary key is a unique identifier for a record in a table.

• For...read more

Joins in SQL are used to combine data from two or more tables based on a related column.

• Joins are used to retrieve data from multiple tables in a single query.

• There are different types of joins such as inner join, left join, right join, and full outer join.

• The join condition is specified using the ON keyword and the related columns.

• Example: SELECT * FROM table1 INNER JOIN table2 ON table1.column = table2.column;

• Joins c...read more

Clustered index determines the physical order of data in a table, while non-clustered index is a separate structure.

• Clustered index sorts and stores the data rows in the table based on their key values.

• Non-clustered index creates a separate structure that contains the key values and a pointer to the data row.

• A table can have only one clustered index, but multiple non-clustered indexes.

• Clustered index is faster for retr...read more

Default fill factor is the percentage of space reserved for future data growth in an index.

• It is set to 0 by default, which means the index will be filled to 100% capacity.

• A fill factor of 80% means that 20% of the index space will be left empty for future growth.

• It can be set at the server, database, or index level.

• It can affect performance and disk space usage.

System databases are the default databases created during SQL Server installation.

• System databases include master, model, msdb, and tempdb.

• Master database stores system-level information.

• Model database is used as a template for new databases.

• Msdb database is used for SQL Server Agent and maintenance plans.

• Tempdb database is used for temporary storage of data.

• System databases cannot be deleted or detached.

• Additional sys...read more

SQL editions are different versions of SQL Server with varying features and capabilities.

• SQL Server Express - free, limited to 10GB database size

• SQL Server Standard - basic features for small to medium businesses

• SQL Server Enterprise - advanced features for large businesses

• SQL Server Developer - full-featured version for development and testing

• SQL Server Web - designed for web applications

• SQL Server Business Intelligen