Indexed sequential access method is the organization of file in an advanced sequential manner. A primary key is used in this method to store records in the file. Also, it generates an index value, and mapping is done with the record. This index stores the address of the file.   If we use the index … Read more

Relational Model Concept Relational model refers to any table with rows and columns. Each row of the table is called a tuple, and each column has a name, also known as an attribute. Domain: It consists of some atomic values of a particular attribute. Attribute: It is the name given to a particular column in … Read more

Functional Dependency The relationship existing between any two attributes is called functional dependency. This kind of relationship is present between the non-key attribute and the primary key inside a table. Functional dependencies come in use for designing or redesign of a relational database which assists to remove redundancy (duplication of data), thus minimizing the chance … Read more

RELATIONAL CALCULUS 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 … Read more

Integrity Constraints The Set of rules which is used to maintain the quality of information are known as integrity constraints. Integrity constraints make sure about data intersection, update and so on. Integrity constraints can be understood as a guard against unintentional damage to the database.   Different types of Integrity Constraints Domain Constraint The Definition … Read more

Join Operations Related tuples are combined from different relations in join operations. This holds valid only if a given join condition is met. Join operations are denoted by ⋈. Example EMPLOYEE Emp_Code Emp _Name 101 Jai 102 Mahesh 103 Vishal   SALARY Emp_Code Emp _Name 101 90000 102 130000 103 125000   Operation: (EMPLOYEE⋈SALARY) RESULT: … Read more

Database Language A Database Management System has all the required interfaces and languages for the purpose of expressing the updates and queries in the database. These database languages can be used for reasons like storing, reading, and updating the data in the database. There are a number of database languages which can be used. These … Read more

Three Schema Architecture The three-schema architecture is commonly known as the three-tier architecture or ANSI/SPARC architecture. These terms and framework are for describing a particular database system structure. The physical database and the user applications are kept separate using this three-tier architecture. This type of architecture has three, which are what keeps the user and … Read more

GENERALIZATION 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 level are capable of combining with the minor level entities in order to develop into a major … Read more

SPECIALIZATION Specialization is considered as a top-down access, which is just the opposite of Generalization. According to the specialty, any higher level entity has the potential to get classified further into two minor level entities. It is also implemented in order to find the subset of any entity set which shares some different characteristics. Firstly, … Read more