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!
a) Suppose we updated the catalog tables in real time, that is, after every update, insert, or delete SQL statement were executed-rather than only running RUNSTATS once every few days or longer.
Is this idea (real time updates), a good idea? Provide arguments both for and against.
b) Suppose the DBMS kept track of how long it took to execute each SQL statement: i.e., for every single SELECT, INSERT, UPDATE, and DELETE statement. Explain how the database system could use this information in some meaningful and practical ways to suggest to the DBA when it is time to reorganize the tables and indexes (or for the DBA to take other action).
c) When should a DBA consider dropping indexes from a table? Give at least 3 good reasons.
Let consider the given partial relation EMP. Let us make some sub-queries for them EMPNO ENAME JOB SAL DEPTNO 7566
A file of employee have 10,000 blocks on a cylinder of a disk with characteristics r=8ms and btt=0.6ms I want to know the cost of read inthe file under following conditions for a q
Vertical Fragmentation- Vertical fragmentation groups together only those attributes in a relation that are used jointly by various important transactions. A vertical fragment is d
Java program for horrizontal fragmentation in distributed database
What is it ?
What are the disadvantages of relational data ? Disadvantages • Performance - If the number of tables among that relationships to be established are large and the tables t
What is the use of unique function? UNIQUE function: If UNIQUE is specified then only unique values are used to computed the mean.
wh
What do you mean by Correlated subquery? Subqueries, or nested queries, are used to bring back a set of rows to be used by the parent query. Depending on how the subquery is writ
Give an example of enforcement in Typing. You can understand the idea of enforcement as it makes sure objects of dissimilar classes may not be interchanged as below: Exampl
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