Relation status is mainly non-procedural query language. The non-procedural query language means that the user has the concern with the various details related to the obtaining of the end results. The relational calculus let us know about what should do you; however, it doesn’t explain about how to do. Kinds of Relational Calculus: Tuple Relational … Read more
Generalization resembles the bottom-up way where two or more entities of minor level combine in order to form a greater level entity only if they possess any attributes that are common amongst them. The entities of higher levels are capable of combining with the minor level entities in order to develop into a major entity … Read more
If it is a case of execution of two or more transactions, the interleaving of logs will occur. It will become very inconvenient for the system of recovery to backtrack every record and start the process of recovering. Most database management systems make use of the concept of “checkpoint” to make the situation more convenient … Read more
Every transaction in DBMS has four distinct properties. These properties are for the maintenance of consistency in the database before, during, and after the execution of the transaction. Properties of the transaction Consistency Atomicity Durability Isolation Consistency Consistency of database occurs through the maintenance of the integrity constraints. The complete execution of the transaction shall … Read more
A transaction in DBMS is a collection of logically related tasks. It consists of a set of operations. A transaction is an assembly of consecutive actions or a single operation that is done by a single operator to execute tasks to access the information of a database. For example: Consider the employee of a bank … Read more
A failure in DBMS is categorized into the following three classifications to ease the process of determining the exact nature of the problem: Transaction failure Disk failure System crash Types of failure Transaction failure A failure in transaction occurs when the transaction is unable to execute or if it reaches a point from where the … Read more
Join dependency in DBMS is a generalization upon the concept of multivalued dependency. Explanation Let the joining of the two relations R1 and R2 with C be equal to the relation that is R. Then it is safe to conclude that there is a join dependency. R1 and R2 constitute the decomposition of R2 (C, … Read more
In DBMS, a file is a set of data records. A primary key helps to access the data records. The type of file organization that utilized for the given collection of data records helps in determining the frequency and type of access. File organization represents a logical equation among the different data records. This function … Read more
Although less prevalent than functional dependency, join dependency and multivalued dependency can guide the design of the database. But inclusion dependency is widespread. It is a statement in which a few of the columns of a relation are in the other columns. Typically, inclusion dependency has a very insignificant influence on the design of a … Read more
While the two or shape of documents are a gift in the same record, it’s miles in acknowledgment as clusters. The one’s documents may additionally have, or more magnificent tables typically gift in the same records block, and critical attributes which might be used to map those tables together are stored certainly as speedy. This … Read more