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A database is the backbone of any IT system. As a Database Developer, I am sure you would want to prove your expertise and knowledge in your next job interview and win a role. Answer: DBMS are software applications that help you build and maintain logically related data also known as the database.
- DBMS Interview Questions
- DBMS - Interview Questions and Answers
- Top 50 DBMS Interview Questions You Need to know
- Top 30 DBMS Interview Questions and Answers
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DBMS Interview Questions
A database is the backbone of any IT system. As a Database Developer, I am sure you would want to prove your expertise and knowledge in your next job interview and win a role. Answer: DBMS are software applications that help you build and maintain logically related data also known as the database. Here are a few advantages of using a DBMS:. Answer: The database is a collection of ordered data, ordered and stored electronically. Such organized data can be easily accessed, aggregated and managed.
Answer: A checkpoint is a point before which all the transactions in the DBMS were committed, and the database was in a consistent state. It is a point when a backup is taken, and all the dirty pages in-memory modified pages and old transaction logs are cleared from the system to release memory space and stored permanently into a storage disk.
For example, a manual checkpoint can be added as follows:. Read more. Answer: Data abstraction is the hiding of irrelevant information from the user so that the interactions with users can be smooth.
There are three levels of abstraction:. A functional dependency expresses relationship between the non-key attributes and the primary key of a table.
A functional dependency is of two types — trivial and non-trivial. Answer: It is a technique for database optimization where redundant data is added to one or more tables to avoid joins. This makes retrieval of data faster and more efficient and simpler queries. Answer: Intention is the constant value, i. It is likely to change frequently. Answer: System R is a database management system that provides a high level of data independence and abstraction of the database from the users.
It has data control features like triggered transactions, authorization, integrity assertions and provisions for data consistency. Answer: All the above are normal forms of data, i. Answer: In DBMS, 2-Tier architecture is a type of database architecture where the UI or view layer also called the presentation runs on a client machine desktop, laptop, tablet, phone, etc. Answer: Normalization is an important process that removes redundancy from a set of relations.
It can reduce the irregularities in the insert, delete and update by dividing huge tables into smaller tables and use keys to link them. For example,. Answer: Atomicity means that all the actions are carried out at once, or none is carried out. This means that if a transaction is incomplete or fails in between everything will be rolled back to a previous stable state. We use aggregation to express relationships between various entities.
Answer: Correlated subqueries are subqueries that are executed once for each row processed by its main statement. Answer: The two-tier architecture follows a client-server architecture. There is a straight communication link between client and server.
Two-tier architecture gives high performance as there is no middle layer. The client can be any device like mobile, desktop, laptop etc. Answer: Stored procedures can be invoked explicitly by the user. It can take certain input parameters and can return output values. It is just like any other program. Triggers are called spontaneously on its own when a specific event occurs. Answer: Deadlock happens when a set of processes are blocked.
Each process is holding up a resource that the other process requires. The other process is waiting for a resource to be released by the same or another process. Deadlock can be depicted as:. Answer: In a hierarchical database model, data is organized into nodes in a tree-like structure. A node is connected to only one parent node above it. Hence data in this model has a one-to-many relationship. Answer: The network database model is a refined version of a hierarchical model.
Here too, data is organized in a tree-like structure. However, one child node can be connected to multiple parent nodes.
This gives rise to a many-to-many relationship between data nodes. Answer: A relational database is organized into tables, records, and column and there is a well-defined relationship between database tables. A relational database management system RDBMS is an application that allows you to create, update, and administer a relational database.
Tables communicate and share the information which enables data search, data organization, and reporting. Answer: In an object-oriented database model, data is represented by objects. For example, a multimedia file or record in a relational database is stored as a data object as opposed to an alphanumeric value. SQL language is relatively easy to write, read, and interpret. Answer: A database index is a data structure that improves the speed of data retrieval operations on a database.
The procedure of boosting the collection of indexes is named as Index hunting. It is done by using methods like query optimization and query distribution. Answer: A distributed database is a collection of multiple interconnected databases that are spread physically across various locations. The databases can be on the same network or on multiple networks.
Answer: Database partitioning is a process where a logical database is divided into distinct independent parts. The database objects like tables, indexes are subdivided and managed and accessed at the granular level. Answer: Partitioning is a powerful functionality that increases performance with decreased cost. It enhances manageability and improves the availability of data. How data is to be accessed is predetermined hence it is more swift and efficient. The SQL statements are compiled at compile time.
Answer: In a dynamic SQL, SQL statements are constructed at runtime, for example, the application can allow the user to create the queries.
Basically, you can build your query at runtime. It is comparatively slower than the static SQL as the query is compiled at runtime. Answer: Data Warehousing is a technique that aggregates a large amount of data from one or more sources.
Data analysis is performed on the data to make strategic business decisions for organizations. Answer: MySQL is an open-source relational database management system, which stores data in tables and maintains a relationship between the data. It uses the most powerful query language SQL Structured Query Language for database access and has a very powerful syntax to create simple and complex queries to retrieve and structure data. Data in MySQL is organized and conforms to a certain format, and hence it is the most popular structured database today.
Answer: MongoDB is a non-relational unstructured open-source database. This document-oriented database stores your data in collections made out of individual documents. Answer: Business intelligence BI is a technology-driven process for analyzing data and presenting information to help executives, managers, and other corporate end-users make business decisions.
The tools are user-friendly that helps you gather data from varied sources for analysis. They are as follows:. Answer: An entity-relationship model or an entity-relationship diagram is a visual representation of data which is represented as entities, attributes and relationships are set between entities.
Answer: An entity can be a real-world object, which can be easily identifiable. For example, in a library database, books, publishers and members can be considered entities. All these entities have some attributes or properties that give them their identity. In an ER model, the entities are related to each other. Answer: Data mining is a process of sorting through a large amount of data to identify patterns and trends.
It uses complex mathematical and statistical algorithms to segment data for the prediction of likely outcomes. Answer: Query optimization is an important feature when it comes to the performance of a database. Identifying an efficient execution plan for evaluating and executing a query that has the least estimated cost and time is referred to as query optimization.
Answer: A catalog is a table that contains the information such as the structure of each file, the type, and storage format of each data item and various constraints on the data. The information stored in the catalog is called Metadata. One-to-one — A row in one table A is related to only one row in another table B One-to-many — A row in a table A is linked to many rows in another table B.
But a row in table B is linked to only one row in table A. Many-to-many — A row in the table A is linked to many rows in the table B and vice-versa. Answer: Addition, deletion, and modification are the most important primitive operations common to all DBMS. Answer: In SQL Structured Query Language , the term cardinality refers to the uniqueness of data values contained in a particular column attribute of a database table.
The lower the cardinality, the more are the duplicated values in a column. It is very stable and robust hence popular. Answer: Indexes can be created to enforce uniqueness, to facilitate sorting, and to enable fast retrieval by column values. When a column is frequently used it is a good candidate for an index to be used with suitable conditions in WHERE clauses.
Answer: Hashing is the transformation of a string of characters into a usually shorter fixed-length value or key that represents the original string.
DBMS - Interview Questions and Answers
Solved examples with detailed answer description, explanation are given and it would be easy to understand. View the solution for the problems with feel and good user interface; easily go through all questions and answers. You can easily answer the interview questions based on DBMS by practicing the exercises given below. All Rights Reserved. Contact us: info.
DBMS is a collection of programs that facilitates users to create and maintain a database. In other words, DBMS provides us an interface or tool for performing different operations such as the creation of a database, inserting data into it, deleting data from it, updating the data, etc. DBMS is a software in which data is stored in a more secure way as compared to the file-based system. Using DBMS, we can overcome many problems such as- data redundancy, data inconsistency, easy access, more organized and understandable, and so on. A Database is a logical, consistent and organized collection of data that it can easily be accessed, managed and updated. Databases, also known as electronic databases are structured to provide the facility of creation, insertion, updating of the data efficiently and are stored in the form of a file or set of files, on the magnetic disk, tapes and another sort of secondary devices. Database mostly consists of the objects tables , and tables include of the records and fields.
V. Enforcing integrity constraints. 5. What is normalization? Page 2. 20/08/15 pm. DBMS Interview Questions-Interview Questions and Answers Page 2.
Top 50 DBMS Interview Questions You Need to know
While you should be updated with the latest trends in the industry, your basics should also be strong on the other hand. Given below is a list of most popular Database interview questions and answers for your reference. Answer: Database is an organized collection of related data where the data is stored and organized to serve some specific purpose. For Example , A librarian maintain a database of all the information related to the books that are available in the library.
Are you looking to join industry as a DBMS developer? Have you prepared yourself to face DBMS interview questions? If not, then dig into some technical insights for DBMS.
Top 30 DBMS Interview Questions and Answers
What are advantages of DBMS over traditional file based systems? Ans: Database management systems were developed to handle the following difficulties of typical Fille-processing systems supported by conventional operating systems. Data redundancy and inconsistency 2. Difficulty in accessing data 3. Data isolation — multiple files and formats 4. Integrity problems 5. Atomicity of updates 6.
Basically, out of my personal experience, there is not any specific way or formula to get through an Interview Process and it totally depends on you and the type of Interviewer. This article includes almost all the important DBMS interview questions, covering the basic concepts in simple terms along with examples for your easy understanding. This is a system that allows its user to store the data, define it, retrieve it and update the information about the data inside the database.
A prearranged collection of figures known as data is called database. Database Management Systems DBMS are applications designed especially which enable user interaction with other applications. Edgar F. Codd proposed the relational model in A database language may also incorporate features like: DBMS-specific Configuration and management of storage engine Computations to modification of query results by computations, like summing, counting, averaging, grouping, sorting and cross-referencing Constraint enforcement Application Programming Interface 7 What do database languages do? As special-purpose languages, they have: Data definition language Data manipulation language Query language 8 Define database model.
Девушка высвободилась из его рук, и тут он снова увидел ее локоть. Она проследила за его взглядом, прикованным к синеватой сыпи. - Ужас, правда. Беккер кивнул. - Ты же сказала, что не колешься.