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Define entity integrity and referential integrity. How does SQL allow specification of these?
Ans: Entity Integrity Rule- If the attribute A of relation R is a prime attribute of R after that A cannot accept null values.
Referential Integrity Rule- In referential integrity, it is made sure that a value that appears in one relation for a given set of attributes as well appears for a particular set of attributes in another relation.
In SQL, referential integrity and entity integrity rules are implemented as constraints on the relation known as reference Key constraint and primary Key constraint correspondingly.
These constraints can be fixed with relation at the time of creation of the relations or after the creation of the relations by altering the definition of the relations. For instance:
What is a guard condition? Explain it with a suitable example. The guard-condition is a Boolean expression written with respect to parameters of triggering event and attributes
normal forms
In Oracle what is system global area and how is it organized? The SGA is a collection of shared memory fields which along with the Oracle processes constitute an Oracle instan
Synonyms It allows short names or alternative names for objects. Example : CREATE SYNONYM D30 FOR EMPD30; Now if we give command:
These are the binary operations; i.e., each is applied to two relations or sets. These two relations can be union compatible excluding in case of Cartesian product. Two relations R
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Explain TPS concurreny executions stating their advantages in online business advancement
What do you understand by ACID? - ACID (Atomicity Consistency Isolation Durability) is a quality sought after in a reliable database. Here's the relevance of each quality:
What is Normalization? Database normalization is a data design and organization method applied to data structures based on rules that help building relational databases. In rel
Project Description: This is going to be a School portal to handle each activities in school such as, School fees payment, online registration and every other payment, course re
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