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!
Eliminate Redundant Data
In the "Database Relation" above, the primary key is made up of the D-ID and the Emp-ID. The database-name relies only on the D-ID. The similar database-name will appear redundantly every time its associated D-ID appears in the Database Relation. The database relation has redundancy, for example D-ID value 4 is oracle is repetitive twice. In addition, it also experiences insertion anomaly that is we cannot enter Sybase in the relation as no employee has that skill.
The deletion anomaly also exists. For instance, if we remove employee with Emp-ID 3; no employee with FoxPro knowledge lefts and the information that D-ID 3 is the code of FoxPro will be gone.
To avoid these troubles, we require second normal form. To achieve this, we isolate the attributes depending on both parts of the key from those depending only on the D- ID. This result in two relations: "Database" which gives the name for every D-ID,
and "Emp-database" which lists the databases for each employee. The employee relation is already in 2NF as all the EMP-ID determines all different attributes
Employee Relation
Emp-ID
Emp-Name
1
Gurpreet Malhotra
2
Faisal Khan
3
Manisha Kukreja
4
Sameer Singh
Emp-database
Relation
D-ID
Database Relation
Database
Access
DB2
FoxPro
Oracle
Define the phases of two phase locking protocol Growing phase: a transaction may get locks but not release any lock. Shrinking phase: a transaction might be release locks bu
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
Package classes and associations into models Programs are made of separate physical units which could be edited, imported, complied or otherwise manipulated. The careful part
Define average seek time. The average seek time is the average of the seek times, calculated over a sequence of random requests.
Consider the subsequent relations along with keys underlined Street (name, location, city) House (number, street_name) Lives (name, house_number) Define the above relations
What is DataWarehousing? Subject-oriented, meaning that the data in the database is organized so that all the data elements relating to the similar real-world event or object
Why are cursors necessary in embedded SQL? A cursor is an object used to store the output of a query for row-by-row processing through the application programs. SQL statements
What are the properties in a relation ? In a relation Ordering of rows is immaterial and No two rows are identical.
Multiple column Queries: Syntax: SELECT COLUMN1, COL2,...... FROM TABLE WHERE (COLUMN1, COL2, ...) IN (SELECT COLUMN1, COL2,.... FROM TABLE WHERE );
Express the following queries in SQL: (a) Write the SQL code that will create ALL the four tables given in the appendix. Your answer should not contain the primary key and
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