Normalisation

what are the benefits of using normalisation?

-There is no reiterating data so the table/database is smaller resulting in less money needing to be spent on storage -There is less datas to search throught it is easier to run a query -There is better integerety on the data as none of it is repeated

What are the problems with using normalisation?

-You can end up with more tables than an unormalised database -With more tables it can become more complex to run a query -The more complex the database the longer it takes to run a query

what are the characteristics of a table in 1st normal form ?

1.the data cannot be repeated 2.each piece of data cannot be broken down any further than displayed(Atomic) 3.each row has a primary key 4.each field name is unique

what are the characteristics of a table in 3rd normal form ?

1.the table must already be in 2nd normal form 2.there are no non-key attributes that depend on other non-key attributes

what are the characteristics of a table in 2nd normal form ?

1.the table must be in first normal form 2.all non-key attributes must depend entirely on the primary key

What is normalisation?

Normalisation is a technique for designing relational database tables to prevent duplication of data