List the armstrong axioms for functional dependencies, Database Management System

Assignment Help:

List the Armstrong's axioms for functional dependencies.  What do you understand by soundness and completeness of these axioms?    

 Ans: The Armstrong's axioms are:

  • F1: Relexivity: If X is a set of attributes and Y ⊆ X afterwards X →Y holds.
  • F2: Augmentation: If X → Y holds and Z is a set of attributes afterwards XZ →YZ.
  • F3: Transitivity: {X → Y, Y → Z} |= {X→Z}

 

Soundness: By sound, we mean that a specified set of functional dependencies F specified on a relation schema R, any dependency which we can infer from F by using F1 by F3 holds in each relation state r of R that satisfies the dependencies in F.

Completeness: By complete, we mean that by using F1 through F3 frequently to infer dependencies until no more dependencies can be inferred results in the whole set of all possible dependencies which can be inferred from F.


Related Discussions:- List the armstrong axioms for functional dependencies

Maping constraits, #question.what is mapping constraints and types?.

#question.what is mapping constraints and types?.

Normalization-e-r mapping , Normalize the following table upto and includin...

Normalize the following table upto and including the 3NF. Submit a 1 page printout of only the final set of normalized tables in Data Architect. Just use Data Architect to do the t

Give the forms of triggers, Give the forms of triggers? The triggering ...

Give the forms of triggers? The triggering event can be insert or delete. For updated the trigger can state columns. The referencing old row as clause The referencing

Explain th process to avoid re-computation, Saving Derived Attributes to Av...

Saving Derived Attributes to Avoid Re-computation Data that is derived from other data should be stored in the computed form to avoid re-computation. For this, we could define

Data handling and research methods, Data Handling and Research Methods: ...

Data Handling and Research Methods: The dataset encompassing 130 participants contains several variables measuring detrimental health related behaviours referring to the use o

Digital, #floating point representation is used to store

#floating point representation is used to store

What is stored procedure, What is Stored Procedure? A stored procedure ...

What is Stored Procedure? A stored procedure is a named group of SQL statements that have been previously formed and kept in the server database. Stored procedures accept input

Define data independence, Data independence seems that "the application is...

Data independence seems that "the application is independent of the access strategy and storage structure of data". In other words, the ability to change the schema definition in o

Exclusive lock, Exclusive lock It is asked for by a transaction on...

Exclusive lock It is asked for by a transaction on a data item that it wants to update. No other transaction can put either a shared lock or an exclusive lock on a dat

Dbms, Retrieve the S&S In-Chapter Database (in Microsoft Access format) fro...

Retrieve the S&S In-Chapter Database (in Microsoft Access format) from the text's Web site (or create the tables in Table 4-5 in a relational DBMS product). Write queries to answer

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