Explain why normalization is important to database design. Describe the fourth normal form (4NF) of normalization. Why is important to denormalize some tables of a database?
Normalization is important in database because it allows the logical, efficient storage of data within tables. Normalization allows for the elimination of redundant data and allows only related data to be stored in a specific table.
QUESTION 2
The Fourth Normal Form follows all the requirements of the other 3 forms before it meaning it follows in chronological order for 1NF to 3NF then it adds an addition requirement stating a relation is in 4NF if it has no multi-valued dependencies.
QUESTION 3
Denormalizing some tables within a database is done so to improve system performance. This is because of some of the excessive relationships caused by the normalization of the database creating many smaller related tables. De normalizing should only be attempted by professionals who have the necessary tools to check database system performance.
Most of the answers are pretty straightforward, however concernin denormalization, is this necessary to do since it requires professionals to do it?
What i don't fully understand, is how it improves performance by doing the exact opposite of normalization which is adding redundant data to the database.
As you go higher in the normalization process, more complex joins or relationships are created which requires more more complex computations and processes for the RDBMS. It could therefore mean that higher normal forms, although they may be desired for the design because they add useful functionality, may therefore cause databases to be less efficient. Therefore de-normalization will be desirable. For example, converting a table from 4NF to 3NF could be done to improve the performance of the database. Hope this helps.
i agree with arnesh that the importance of normalization is to eliminate the need for redundant data and to only store the related information within the table.
ok i think that denormalization is used in some cases because sometimes the higher normal form is not the best choice to use.so we denormalize the table to attain better performance .
I am a lecturer at the University of Guyana, Berbice Campus in the Department of Computer Science. I am also currently the coordinator of the Division of Natural Sciences at the campus.
QUESTION 1
ReplyDeleteNormalization is important in database because it allows the logical, efficient storage of data within tables. Normalization allows for the elimination of redundant data and allows only related data to be stored in a specific table.
QUESTION 2
The Fourth Normal Form follows all the requirements of the other 3 forms before it meaning it follows in chronological order for 1NF to 3NF then it adds an addition requirement stating a relation is in 4NF if it has no multi-valued dependencies.
QUESTION 3
Denormalizing some tables within a database is done so to improve system performance. This is because of some of the excessive relationships caused by the normalization of the database creating many smaller related tables. De normalizing should only be attempted by professionals who have the necessary tools to check database system performance.
Most of the answers are pretty straightforward, however concernin denormalization, is this necessary to do since it requires professionals to do it?
ReplyDeleteWhat i don't fully understand, is how it improves performance by doing the exact opposite of normalization which is adding redundant data to the database.
Awaiting response...
As you go higher in the normalization process, more complex joins or relationships are created which requires more more complex computations and processes for the RDBMS. It could therefore mean that higher normal forms, although they may be desired for the design because they add useful functionality, may therefore cause databases to be less efficient. Therefore de-normalization will be desirable. For example, converting a table from 4NF to 3NF could be done to improve the performance of the database. Hope this helps.
ReplyDeletei agree with arnesh that the importance of normalization is to eliminate the need for redundant data and to only store the related information within the table.
ReplyDeleteok i think that denormalization is used in some cases because sometimes the higher normal form is not the best choice to use.so we denormalize the table to attain better performance .