In parallel database system data processing performance is improved by using multiple resources in parallel. In this CPU, disks are used parallel to enhance the processing performance. Operations like data loading and query processing are performed parallel. Centralized and client server database systems are not powerful enough to handle applications that need fast processing. Parallel database systems have great advantages for online transaction processing and decision support applications. Parallel processing divides a large task into multiple tasks and each task is performed concurrently on several nodes. This gives a larger task to complete more quickly. Architectural Models There are several ... Read More

A parallel database is one which involves multiple processors and working in parallel on the database used to provide the services.A parallel database system seeks to improve performance through parallelization of various operations like loading data, building index and evaluating queries parallel systems improve processing and I/O speeds by using multiple CPU’s and disks in parallel.Working of parallel databaseLet us discuss how parallel database works in step by step manner −Step 1 − Parallel processing divides a large task into many smaller tasks and executes the smaller tasks concurrently on several CPU’s and completes it more quickly.Step 2 − The ... Read More

Data Abstraction is a process of hiding unwanted or irrelevant details from the end user. It provides a different view and helps in achieving data independence which is used to enhance the security of data.The database systems consist of complicated data structures and relations. For users to access the data easily, these complications are kept hidden, and only the relevant part of the database is made accessible to the users through data abstraction.Levels of abstraction for DBMSDatabase systems include complex data-structures. In terms of retrieval of data, reduce complexity in terms of usability of users and in order to make ... Read More

Database management system (DBMS) is a software or tool which can be used for managing and maintaining the data within the database.Major Capabilities of DBMSThe major capabilities of DBMS are listed below −Data StorageData RetrievalData UpdateSecurityData IndependenceExplanationGenerally a person has to work with a huge amount of information every day. In order to interact with the large amount of data we need a system where we can store, manipulate, security, sharing the information all over the world. It is a core reason the industries are maintaining database management tools.Powerful Relational DBMSThe relational DBMS is more powerful because of the reasons ... Read More

The database security is broadly classified into physical and logical security. Database recovery is the way of restoring a database to a correct state in the event of a failure.Physical security − Physical security refers to the security of the hardware that is associated with the system and the protection of the site where the computer resides. The natural events like fire, floods, and earthquakes can be considered as some of the physical threats. It is advisable to have backup copies of databases in the face of massive disasters.Logical security − Logical security refers to the security measures present in ... Read More

Query Processing is a translation of high-level queries into low-level expression. It is a step wise process that can be used at the physical level of the file system, query optimization and actual execution of the query to get the result.It requires the basic concepts of relational algebra and file structure. It refers to the range of activities that are involved in extracting data from the database. It includes translation of queries in high-level database languages into expressions that can be implemented at the physical level of the file system.Given below is the diagram that shows the steps of the ... Read More

In parallel database system data processing performance is improved by using multiple resources in parallel. In this CPU, the disk is used parallel to enhance the processing performance.Operations like data loading and query processing are performed parallel. The centralized and client server database systems are not powerful enough to handle applications which need fast processing.Parallel database systems have great advantages for online transaction processing and decision support applications. Parallel processing divides a large task into multiple tasks and each task is performed concurrently on several nodes. This gives a larger task to complete more quickly.Architectural ModelsThere are several architectural models ... Read More

Logical Database Design has a low-level description of entities that are defined and how they are related to each other and what kind of data is to be stored. This model determines if all the requirements of the business have been gathered.Physical Database Design deals with how the data will be stored in the database using suitable DBMS and this design is generally created by database administrators and developers.DifferencesThe major differences between logical database design and physical database design are as follows −Logical Database DesignPhysical Database DesignThat describes the data without regard to how they will be physically implemented in ... Read More

Physical database designing is used for good performance while the process of structuring data in the storage.Factors influencing physical database designLet us see the important factors that influence physical database design −Transactions and queriesIt is important to understand what kind of transactions and queries will be run and what use will the database serve.Following information about the queries should be needed −Files that will query access.Selection conditions to be specified for the query.Type of selection conditions to be used in query whether equality, range, or inequality.Join conditions to be used in the query.Need for linking tables for query optimization.Following information ... Read More

For any stored data if we want to preserve the consistency and correctness, a relational DBMS typically imposes one or more data integrity constraints. These constraints restrict the data values which can be inserted into the database or created by a database update.Data Integrity ConstraintsThere are different types of data integrity constraints that are commonly found in relational databases, including the following −Required data − Some columns in a database contain a valid data value in each row; they are not allowed to contain NULL values. In the sample database, every order has an associated customer who placed the order. ... Read More