Question 1. When Is A Functional Dependency F Said To Be Minimal?

Answer :

Every dependency in F has a single characteristic for its right hand aspect.

It can not replace any dependency X -->A in F with a dependency Y--> A where Y is a right subset of X and now have a hard and fast of dependency that is equal to F.

We can't remove any dependency from F and also have set of dependency this is equivalent to F.

Question 2. What Is Operational Data Store?

Answer :

An operational statistics save (or "ODS") is a database designed to combine records from more than one assets to make analysis and reporting easier.

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Question 3. What Is Multivalued Dependency?

Answer :

Multivalued dependency denoted by means of X-->Y particular on relation schema R, where X and Y are both subsets of R, specifies the subsequent constraint on any relation r of R: if two tuples t1 and t2 exist in r such that t1[X] = t2[X] then t3 and t4 should also exist in r with the following residences

t3[x] = t4[X] = t1[X] = t2[X]

t3[Y] = t1[Y] and t4[Y] = t2[Y]

t3[Z] = t2[Z] and t4[Z] = t1[Z]

in which [Z = (R-(X U Y)) ]

Question 4. What Is Ddl (facts Definition Language)?

Answer :

A facts base schema is detailed by way of a fixed of definitions expressed by way of a special language referred to as DDL.

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Question 5. What Is Vdl (view Definition Language)?

Answer :

It specifies person perspectives and their mappings to the conceptual schema.

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Question 6. What Is Degree Of A Relation?

Answer :

It is the variety of characteristic of its relation schema.

Question 7. What Is A Relation Schema And A Relation?

Answer :

A relation Schema denoted via R(A1, A2, ?, An) is made of the relation call R and the listing of attributes Ai that it incorporates. A relation is defined as a fixed of tuples. Let r be the relation which includes set tuples (t1, t2, t3, ..., tn). Each tuple is an ordered list of n-values t=(v1,v2, ..., vn).

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Question eight. How Does Tuple-orientated Relational Calculus Differ From Domain-oriented Relational Calculus?

Answer :

The tuple-orientated calculus uses a tuple variables i.E., variable whose handiest authorized values are tuples of that relation. E.G. QUEL

The area-orientated calculus has area variables i.E., variables that variety over the underlying domain names rather than over relation. E.G. ILL, DEDUCE.

Question 9. What Is Relationship?

Answer :

It is an association amongst two or greater entities.

Relationship Set - The collection (or set) of similar relationships.

Relationship Type - Relationship kind defines a hard and fast of associations or a dating set among a given set of entity kinds.

Degree of Relationship Type - It is the quantity of entity kind taking part.

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Question 10. What Is Normalization?

Answer :

It is a manner of analysing the given relation schemas primarily based on their Functional Dependencies (FDs) and primary key to gain the houses.

Minimizing redundancy

Minimizing insertion, deletion and replace anomalies.

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Question eleven. What Is Functional Dependency?

Answer :

Functional dependency is denoted with the aid of X --> Y between sets of attributes X and Y that are subsets of R specifies a constraint at the feasible tuple that could shape a relation kingdom r of R. The constraint is for any two tuples t1 and t2 in r if t1[X] = t2[X] then they have got t1[Y] = t2[Y]. This way the fee of X component of a tuple uniquely determines the value of factor Y.

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