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Update Operations and Dealing with Constraint Violations
There are three basic operations to be executes on relations:
The INSERT Operation:
The insert operation permits us to insert a new tuple in a relation. When we try to insert a new record, then any of the following four types of constraints can be violated:
• Entity Integrity constraint: If the primary key attribute value of new tuple t is given as null.
What's the difference between a primary key and a unique key? Both primary key and unique key enforces uniqueness of the column on which they are explained. But by default prim
Example -Find the employee name, salary, department number and average salary of his/her department, for those employees whose salary is more than the average salary of that depart
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Timestamps For Read operations: If TS (T) If TS (T) >= W-timestamp (Q), then the transaction T is trying to read a value of data item Q which has been written and committed
which component of DBMS can be embedded in a program? The data manipulation language (DML) is a component which is embedded in a program.
Scenario: You are a freelance database designer who has just been contacted by a small software development company named Altair Software. The president of the company has asked
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A student entity type has the following attributes,name..
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Explain the uses of deadlock It will lead to deadlock since this is the only place where incoming acknowledgements are processed. Without this code, sender will keep timing ou
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