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!
What are the problems if one were not to normalize? When do these problems surface?
Ans: Database normalization, sometimes considered to as canonical synthesis, is a method for designing relational database tables to minimize duplication of information and, in so doing, to preserve the database against specific types of logical or structural problems, that are data anomalies. For instance, when multiple instances of a given piece of information take place in a table, the possibility exists that these examples will not be kept consistent while the data within the table is updated, leading to a loss of data integrity. A table that is adequately normalized is less vulnerable to problems of this type, as its structure reflects the basic assumptions for while multiple instances of similar information should be denoted by a single instance only.
define anomalies and different types of anomalies with example
Attributes that are directly kept in the data base. For example, 'Birth date' attribute of a person. Derived Attributes that are not stored directly but can be derived
What does data dictionary is a special file contains ? The data dictionary is a special file contain The name of all fields in all files.The width of all fields in all files an
Concatenation operator Example : Printing name and job as one string as column name employees: SELECT ENAME||JOB "EMPLOYEES" FROM EMP;
What are the disadvantages of relational data ? Disadvantages • Performance - If the number of tables among that relationships to be established are large and the tables t
Define Specialisation and generalization in brief? Specialisation / generalization: Generalization or Specialization represents the is a relationship set, an necessary element
Define average seek time. The average seek time is the average of the seek times, calculated over a sequence of random requests.
Explain Hierarchical Model ? Hierarchical Model - It was established to model several kinds of hierarchical organizations which exist in the real world. It uses tree structur
How are tables stored on Disk? We realise that every record of a table can have different amounts of data. This is due to in some records; some attribute values may be "zero".
Explain the term- Periodic recomputation Periodic recomputation: Base values are often updated in bunches. Sometimes, it is possible to just recompute all derived attributes p
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