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 view in RDBMS?
View - A view is a relation (virtual rather than base) and could be used in query expressions, which is, queries can be written by using the view as a relation. Instead, a view is a named table in which is represented, not through its own physically separate stored data, but through its definition in terms of other named tables (base tables or views). The base relations on that a view is based are sometimes known as the existing relations. The definition of a view in a create view statement is stored within the system catalog. The syntax to create a view is:
CREATE [OR REPLACE] VIEW [()] AS
WITH {READ ONLY|CHECK OPTION [CONSTRAINT
]};
why older data models are being replaced by new data models.
Explain the Concept of Two-phase Locking It concerns the positions of locking and unlocking operations in each transaction. In this protocol every transaction issue lock and u
Data Definition Language It organises the data in the form of columns and rows. But what does the data field column of table accumulate? How do you describe it using SQL? Th
explain the steps for reduction of er model into relational model?
What is serializability? Explain its types? The data base system must control concurrent implementation of transactions, to ensure that the data base state remains consistent.
Explain what is Aggregation ? Aggregation: This is used whenever we intend to show a relationship between an entity and the relationship. There is no provision for this in th
What are views? Explain how views are different from tables? A view in SQL terminology is a one table in which is derived from other tables. These other tables could be base t
how to design tables
Explain what is DDL? DDL - Data Definition Language: statements used to define the database structure or schema. Some examples: CREATE - to create objects in the database ALT
What is Nested Queries explain in details? Nested Queries - A SELECT query could have subquery(s) in it. While a SELECT query having another SELECT query in it, is known as n
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