Q. For a weak entity set to be meaningful, it must be associated with another entity set in combination with some of their attribute values, is called as :

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Q. Which of the following statements is FALSE about weak entity set ?

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Q. Let E1 and E2 be two entities in E-R diagram with simple single valued attributes. R1 and R2 are two relationships between E1 and E2 where R1 is one - many and R2 is many - many. R1 and R2 do not have any attribute of their own. How many minimum number of tables are required to represent this situation in the Relational Model?

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Q. The STUDENT information in a university stored in the relation STUDENT (Name, SEX, Marks, DEPT_Name)
Consider the following SQL Query SELECT DEPT_Name from STUDENT where SEX = 'M' group by DEPT_Name having avg (Marks)>SELECT avg (Marks) from STUDENT. It returns the Name of the Department for which:

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Q. Select the 'False' statement from the following statements about Normal Forms :

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Q. The Relation Vendor Order (V_no, V_ord_no, V_name, Qty_sup, unit_price) is in 2NF because:

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Q. The relation schemas R1 and R2 form a Lossless join decomposition of R if and only if :

(a)          R1⌒ R2 ⇒ (R1- R2)

(b)          R1→ R2

(c)          R1⌒ R2 ⇒ (R1- R2)

(d)         R2→ R1⌒R2

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Q. In the indexed scheme of blocks to a file, the maximum possible size of the file depends on :

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Q. Consider the following relational schemas for a library database: 
Book (Title, Author, Catalog_no, Publisher, Year, Price) 
Collection (Title, Author, with the following dependencies :

I. Title, Author —> Catalog_no
II. Catalog_no —> Title, Author, Publisher, Year
III. Publisher, Title, Year —> Price
Assume (Author, Title) is the key for both schemas. Which one of the following is true ?

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Q. Specialization Lattice stands for

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Q.
Match the following with respect to the jump statements

List-I List-II

a. Timeout ordering protocol i. Wait for graph

b. Deadlock prevention ii. Roll back

c. Deadlock detection iii. Wait-die scheme

d. Deadlock recovery iv. Thomas Write Rule

Codes:
a b c d

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Q. Consider the schema

R = {S,T, U,V}

and the dependencies

S →T, T → U, U → V and V → S

If   R   =   (R1  and   R2)   be   a decomposition such that R1 ∩ R2 = Ф

then the decomposition is

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Q. Which of the following concurrency protocol ensures both conflict serializability deadlock:
I. 2-phase locking 
II. Time phase ordering 

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Q. The "part-whole", or "a-part-of", relationship in which objects representing the components of something associated with an object representing the entire assembly is called as

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Q. If h is chosen from a universal collection of hash functions and is used to hash n keys into a table of size m, where n ≤ m, the expected number of collisions involving a particular key K is

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Q. In RDBMS, the constraint that no key attribute (column) may be NULL is referred to as:

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Q. Which of the following statement(s) is/are FALSE in the context of Relational DBMS ? I. Views in a database system are important because they help with access control by allowing users to see only a particular subset of the data in the database. II. E-R diagrams are useful to logically model concepts. III. An update anomaly is when it is not possible to store information unless some other, unrelated information is stored as well. IV. SQL is a procedural language.

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Q. In a relational database model, NULL values can be used for all but which one of the following?

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Q. Consider the following two commands C1 and C2 on the relation R from an SQL database:
C1: drop table R;
C2: delete from R;
Which of the following statements is TRUE?
I. Both C1 and C2 delete the schema for R.
II. C2 retains relation R, but deletes all tuples in R.
III. C1 deletes not only all tuples of R, but also the schema for R.

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Q. Consider the following database table having A, B, C and D as its four attributes and four possible candidate keys (I, II, III and IV) for this table:
A B C D
a1 b1 c1 d1
a2 b3 c3 d1
a1 b2 c1 d2

I: {B} II: {B, C} III: {A, D} IV: {C, D}
If different symbols stand for different values in the table (e.g., d1 is definitely not equal to d2), then which of the above could not be the candidate key for the database table?

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