![]() ![]() Check this DBMS Tutorial by Scaler Topics.Įxamples of popular DBMS systems are file systems, XML, Windows Registry, etc. in a database and makes it more convenient and organized to use it. A DBMS system helps a user to overcome problems like data inconsistency, data redundancy, etc. It is software that enables the storage of data more compactly and securely as compared to a file-based system. DBMS provides a tool or an interface for performing various operations such as inserting, deleting, updating, etc. What is DBMS and what is its utility? Explain RDBMS with examples.ĭBMS stands for Database Management System, is a set of applications or programs that enable users to create and maintain a database. Explain the difference between a 2-tier and 3-tier architecture in a DBMS.ĭBMS Basic Interview Questions 1. Explain different types of keys in a database. Explain different types of Normalization forms in a DBMS. What is meant by normalization and denormalization? Explain the major difference between a shared lock and an exclusive lock during a transaction in a database. Explain the difference between the DELETE and TRUNCATE command in a DBMS. Explain the difference between intension and extension in a database. Explain different types of relationships amongst tables in a DBMS. What is meant by an entity-relationship (E-R) model? Explain the terms Entity, Entity Type, and Entity Set in DBMS. Explain different levels of data abstraction in a DBMS. Are NULL values in a database the same as that of blank space or zero? What is meant by ACID properties in DBMS? Explain different languages present in DBMS. Mention the issues with traditional file-based systems that make DBMS a better choice? What is DBMS and what is its utility? Explain RDBMS with examples. For the number of candidate keys to be maximum, k must be ⌊n/2⌋ so that nCk is the maximum for that value. ![]() So for some k, the possible number of candidate keys is nCk, which is n!/(n-k)!k!. These k attributes are randomly chosen from the n attributes. We need to find the value of k such that the number of candidate keys in the relation will be maximum.Īny k attributes at a time constitute one candidate key. Let's say we have a relation R with attributes such that any k of the attributes at a time determines all other attributes. Counting Number of Possible Super Keys in DBMS Example-1 We will use here Inclusive-Exclusive various properties. And also, Student ID, Name, and Email can also form a super key. Here, the combination of Student ID and Name can form a super key. ![]() The definition of a table states that all rows are unique, so the set of all attributes itself is a super key.įor example, if we have a table of students with columns: Student ID, Name, and Email. ![]() All primary or candidate keys are super keys, but not all super keys are primary or candidate keys. So, a primary or candidate key is a super key with no unnecessary attributes. It's different from primary and candidate keys because only the smallest possible super keys can be chosen as primary or candidate keys. What is a Super Key?Ī super key is a group of attributes in a table that can identify each row in that table uniquely. In this article, we will explore the number of possible super keys in a database and their significance. A super key is a set of one or more than one attribute that can uniquely identify a record in a table. In database management systems (DBMS), super keys are an essential concept used to identify unique records in a table. ![]()
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