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What is data sub-language?
A data Sublanguage is a computer language used to define or manipulate the structure of a relational database management system(DBMS) e.g QBE, SQL.
What data structure and logarithm?
data structure is a way of storing data in a computer so that it can be used efficientlyan algorithm is a sequence of instructions, often used for calculation and data processing.Often a carefully chosen data structure will allow the most efficient algorithm to be used.
Which type of data is used to explain a relationship?
A foreign key constraint is used to represent a relationship in a RDBMS (relational database management system).
What the data structure is used behind FACEBOOK?
The GRAPH data structure used behind Facebook.for more detail see
What data structure is used to store homogeneous data item?
array
Describe three commonly used data models?
Enterprise data model, Relational model and ????
What is a record-based data model?
-> A record based data model is used to specify the overall logical structure of the database.-> In this model the database consists of a no. of fixed formats of different types.-> Each record type defines a fixed no. of fields having a fixed length.-> There are 3 principle types of record based data model. They are :1. Hierarchical data model.2. Network data model.3. Relational data model.
What is the advantage of relational database model?
The advantages are as follows: The relational database model is by far the most widely used. It is easier to control, more flexible, and more intuitive than other approaches because it organizes data in tables. The relational model can also be used with personal computers and mainframe systems. It allows tables to be linked. This linkage is especially useful when information is needed from multiple tables.
What do you understand by a Database-Model?
A database model is a theory or specification describing how a database is structured and used. Several such models have been suggested. Common models include: * Hierarchical model * Network model * Relational model * Entity-relationship * Object-relational model * Object model A data model is not just a way of structuring data: it also defines a set of operations that can be performed on the data. The relational model, for example, defines operations such as select, project, and join. Although these operations may not be explicit in a particular query language, they provide the foundation on which a query language is built.
What is a good way to represent a database?
Relational model of database is a good way to represent the database. Also network data model and hierarchical model can be used depending on the requirements.
What is data sub-language?
A data Sublanguage is a computer language used to define or manipulate the structure of a relational database management system(DBMS) e.g QBE, SQL.
What is data sub language?
A data Sublanguage is a computer language used to define or manipulate the structure of a relational database management system(DBMS) e.g QBE, SQL.
Define data models and list different types of data models?
A data model is a collection of concepts that can be used to describe the structure of a database and provides the necessary means to achieve this abstraction whereas structure of a database means the data types,relationships and constraints that should hold on the data. Data model are divided into three different groups they are 1)object based logical model 2)record based logical models 3)physical models Types: Entity-Relationship (E-R) Data Model Object-Oriented Data Model Physical Data Model functional data model
What is post relational data model?
A number of extensions to the relational data model have been proposed in the three decades or so since its invention. Many of these extensions have been implemented in commercial DBMS. What is termed the post-relational data model here is not strictly a data model in that no coherent theory has been developed. Nevertheless it is useful to discuss it here in terms of a set of mech- anisms found in many contemporary DBMS. Such a data model is also referred to by the terms extended-relational and object-relational data model. In Chapter 18 we discuss how the proposed SQL3 standard addresses many of these features. In Chapter 34 we also consider how the ORACLE DBMS supports some of these features. In the first half of the chapter we consider two extensions to the data defin- ition part of the relational data model: abstract data types and nested relations. In the second half of the chapter we consider two constructs - triggers and stored procedures - that have been used both for data manipulation and data integrity purposes. The incorporation of these features into a relational DBMS provides it with the ability to handle complex objects and behaviour. Hence many of the DBMS with these features have termed themselves object-rela- tional systems.
What are the main theories of a relational database approach to storing and accessing data?
The main theories of a relational database approach include the relational model, which organizes data into tables with rows and columns; normalization, which reduces data redundancy and improves data integrity; and SQL (Structured Query Language), which is used to interact with the database for querying and manipulation of data. These theories aim to ensure data consistency, provide flexibility in querying data, and allow for scalability in managing large volumes of data.
Advantages and disadvantages of relational data model?
Advantages of relational data model include data integrity through normalization, flexibility to query data using SQL, and ease of understanding relationships between entities. Disadvantages can include performance issues with complex queries, potential for data duplication across tables, and difficulty in scaling for very large datasets.
What are the different data model in DBMS?
"A data model is a collection of concepts that can be used to describe the structure of a database." Data models can be broadly distinguished into 3 main categories- 1)high-level or conceptual data models (based on entities & relationships) - It provides concepts that are close to the way many users perceive data. 2)lowlevel or physical data models - It provides concepts that describe the details of how data is stored in the computer.These concepts are meant for computer specialist, not for typical end users. 3)representational or implementation data models (record-based,object- 0riented) - It provide concepts that can be understood by end users. These hide some details of data storage but can be implemented on a computer system directly.
