Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Explain Record Based Logical Models?
Record-Based logical Models: Also define data at the conceptual and view levels. Unlike object-oriented models, are used to state overall logical structure of the database, and gives a higher-level description of the implementation. Named so since the database is structured in fixed-format records of various types. Each record type defines a fixed number of fields, or attributes. Each field is commonly of a fixed length (this simplifies the implementation). Record-based models do not involved a mechanism for direct representation of code in the database. Separate languages related along with the model are used to express database queries and updates. The three most widely-accepted models are the relational, network, and hierarchical.
What is transaction? Transaction is a unit of program implementation that accesses and possibly updated several data items.
Object-oriented decompositions Object-oriented decompositions of systems better are able to cope with change. Each subsystem has a well-defined interface which communicates with
What is the meaning of Recovery? In deferred update methods, if a transaction fails before arriving its commit point, it will not have altered the database in any way, so UNDO
WHAT IS MEANT BY E-R MODEL
Before defines the second type of integrity constraint, viz., Entity Integrity, we should be well-known with the concept of NULL. Mostly, NULL is intended as a basis for dealing
Consider the relations described below: PHYSICIAN (regno, name, telno, city) PATIENT (pname, street, city) VISIT (pname, regno, date_of_visit, fee) Where the regno and pname ide
design a generalization specialization hierarchy for a motor vehicle sales company. the company sells motorcycles, passenger cars, vens and buses.
Given the subsequent relations: vehicle (reg_no, make, colour) Person (eno, name, address) Owner (eno, reg_no) Write expressions
Define garbage collection. Garbage may be formed also as a side effect of crashes. Periodically, it is essential to find all the garbage pages and to add them to the list of fr
what is attribute is attribute inheritance in dbms?
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd