Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Consider the relations described below: PHYSICIAN (regno, name, telno, city)PATIENT (pname, street, city) VISIT (pname, regno, date_of_visit, fee) Where the regno and pname identify the physician and the patient uniquely corresponding. Express queries (i) to (iii) in SQL.(i) Get the name and regno of physicians who are in Delhi.(ii) Find out the name and city of patient(s) who visited a physician on 31 August 2004.(iii) Get the name of the physician and the total number of patients who have visited her.(iv) What does the subsequent SQL query answer SELECT DISTINCT nameFROM PHYSICIAN PWHERE NOT EXISTS( SELECT *FROM VISITWHERE regno = p.regno )
(i) Select name, regno from PHYSICIAN where city = ‘Delhi'; (ii) Select pname, city from PATIENT,VISIT where PATIENT.pname=VISIT.pname and date_of_visit = '31-Aug-04'; (iii) select name, count(*) from PHYSICIAN, VISIT where PHYSICIAN.regno = VISIT.regno group by Physician . regno; (iv) This will provide the name of physicians who have not visited any patient.
Describe the four main ways of optimising disk block access. Ans: a. Disk b. Non-volatile writes buffers c. File organization (Clustering) d. Log-based file system
What is an index? An index is a structure that helps to place desired records of a relation quickly, without probing all records.
Short Note on mid Square Method of hashing? Mid square method of hashing: In the method midsquare hashing, the key is squared and the address selected from the center of the s
Advantages And Drawbacks Of Ddbms There are various reasons for building distributed database systems, with sharing of data, reliability and availability, and speedup of query
Determine the term- Active values An active value is that has dependent values. Every dependent value registers itself with active value that contains a set of dependent values
What are the advantages of by using an index and what are its disadvantages ? In difference, if the search key of a secondary index is not a candidate key, it is not sufficient
Explain Alternate key? Alternate Key - All the candidate keys except primary key are known as alternate keys.
Describe the primary key functions? Primary Key : The primary key is an attribute or a set of attributes in which uniquely identify a specific example of an entity. Every entit
wh
Describe the definition of a transaction in SQL Ans: The SQL transaction starts implicitly. Transactions are finished by either Commit work that commits the transaction and st
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd