database

Consider two relations describing teams and players in a sports league: * teams (tid, tname): tid, tname are team-id and team-name, respectively * players(pid, pname, tid): pid, pn...

Consider the database transactions T1 and T2, and data items X and Y. Which of the schedule(s) is/are conflict serializable? Transaction T1 R1(X) W1(Y) R1(X) W1(X) COMMIT(T1) Trans...

Consider the following relational schema: Students (rollno: integer, name: string, age: integer, cgpa: real) Courses (courseno: integer, cname: string, credits: integer) Enrolled (...

Consider the following database tables of a sports league. player (pid,pname, age) coach (cid,cname) team (tid, tname,city,cid) members (pid, tid) An instance of the table and an S...

Let S be the specification: "Instructors teach courses. Students register for courses. Courses are allocated classrooms. Instructors guide students." Which one of the following ER...

Which of the following statements about a relation R in first normal form (1NF) is/are TRUE ?

Consider the following two relations, R(A,B) and S(A,C): The total number of tuples obtained by evaluating the following expression $\sigma_{B<C}(R \bowtie_{R.A=S.A} S)$ is _______...

A functional dependency F: X → Y is termed as a useful functional dependency if and only if it satisfies all the following three conditions: * X is not the empty set. * Y is not th...

An ER model of a database consists of entity types A and B. These are connected by a relationship R which does not have its own attribute. Under which one of the following conditio...

In a B+ tree, if the search-key value is 8 bytes long, the block size is 512 bytes and the block pointer size is 2 bytes, then the maximum order of the B+ tree is _________.

Given the following relation instance $$\eqalign{ & X\,\,\,\,\,Y\,\,\,\,\,Z \cr & \,\,1\,\,\,\,\,\,4\,\,\,\,\,\,2 \cr & \,\,1\,\,\,\,\,\,5\,\,\,\,\,\,3 \cr & \,\,1\,\,\,\,\,\,6\,\,...

There are five records in a database. Name Age Occupation Category Rama 27 CON A Abdul 22 ENG A Jennifer 28 DOC B Maya 32 SER D Dev 24 MUS C There is an index file associated with...