Explain weak and strong entity sets, Database Management System

Assignment Help:

Explain weak and strong entity sets?

Weak and Strong entity sets: A physically powerful entity set has a primary key. All tuples in the group are distinguishable through that key. A weak entity set has no primary key unless attributes of the tough entity set on which it depends are included. Tuples in a weak entity grouped are partition according to their relationship along with tuples within a strong entity set. Tuples inside each partition are discernible by a discriminator, that is a set of attributes. A strong entity set has a primary key. All tuples within the set are distinguishable through that key. A weak entity set has no primary key unless attributes of the strong entity set on that it depends are included. Tuples in a weak entity set are partitioned according to their relationship along with tuples in a strong entity set. Tuples within each partition are discernible through a discriminator that is a set of attributes.


Related Discussions:- Explain weak and strong entity sets

Developer competent in data cleansing-data scrubbing, Data Scrubbing 70,000...

Data Scrubbing 70,000 records Project Description: We need services of a developer competent in data cleansing/Data scrubbing. Scope: - 70,000 records in CSV format.

Ideal data dictionary, An ideal data dictionary should have everything a DB...

An ideal data dictionary should have everything a DBA wants to know about the database. 1 Conceptual, External, and internal database descriptions. 2.    Descriptions of attr

Determine that the checkpoints are a part of, 1. Determine that the Checkpo...

1. Determine that the Checkpoints are a part of  Ans: Checkpoints are a part of Recovery measures

Explain five duties of database administrator, Explain five duties of Datab...

Explain five duties of Database Administrator? 1. DBA administers the three stages of the database and, in consultation along with the whole user community, sets up an defin

Explain recovery process after system failure, Explain recovery process aft...

Explain recovery process after system failure using checkpoint. Ans: Checkpoint scheme or method is an extra component of the log based recovery system. This scheme is used to

Explain the terms primary key, Explain the terms primary key, candidate key...

Explain the terms primary key, candidate key, alternate key and secondary key. In the given table identify every key? STUDENT(SID,Regno, Name, City) Primary Key: The prim

Where and having clause in sql, WHERE and HAVING clause in SQL ? The WH...

WHERE and HAVING clause in SQL ? The WHERE clause is commonly used for implementing conditions on each tuple of the relation. The HAVING clause is used in combination along wi

Define average seek time, Define average seek time. The average seek ti...

Define average seek time. The average seek time is the average of the seek times, calculated over a sequence of random requests.

What is log shipping, What is Log Shipping? Log shipping is the method ...

What is Log Shipping? Log shipping is the method of automating the backup of database and transaction log files on a production SQL server, and then restoring them onto a stand

What is the use of group by clause, What is the use of group by clause? ...

What is the use of group by clause? Group by clause is used to be relevant aggregate functions to a set of tuples. The attributes given in the group by clause are used to shape

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

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!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd