100% satisfaction guarantee Immediately available after payment Both online and in PDF No strings attached
logo-home
Summary A* 9618 Chapter 8: Databases £3.49   Add to cart

Summary

Summary A* 9618 Chapter 8: Databases

 7 views  0 purchase

8.1 Database concepts 8.2 Database management system (DBMS) 8.3 DDL and DML Helped me get A*

Preview 2 out of 14  pages

  • No
  • Chapter 8 : databases
  • September 10, 2024
  • 14
  • 2022/2023
  • Summary
book image

Book Title:

Author(s):

  • Edition:
  • ISBN:
  • Edition:
All documents for this subject (7)
avatar-seller
siennathompson1
8 Databases

8.1 Database concepts

Show understanding of the limitations of using a file-based approach
for the storage and retrieval of data

Data stored in discrete files, stored on computer, and can be accessed,
altered or removed by the user.

Limitations of File Based System:

No enforcing control on organisation/structure of files

Data Redundancy:

Data repeated/duplicated in different files

manually change each

Inconsistent data

Memory wastage

Fixed queries

Programs are written to satisfy particular functions

Sorting must be done manually or must write a new program

Incompatible file formats

Data may be in different format; difficult to find and use other
files.

Impossible for it to be multi-user; chaotic

Security not sophisticated

users can access everything

Each user should only be allowed to access data concerning
their requirements only.




8 Databases 1

, Describe the features of a relational database that address the
limitations of a file-based approach

In a file-based approach, the record structure is fixed, however, in a
relational database, attributes can easily be added/deleted.
Relational databases have a query generator which can reduce the time
taken to produce a new query, in a file-based approach a new program
must be created to produce a query.



Reduced data redundancy/duplication

Data is stored in separate linked tables

Reduced data dependency

Program-data independence

Changes to the data(design) do not require changes to
programs.

E.g. fields can be added or removed without effecting existing
programs

Improved data integrity

Data only needs to be updated once/is only stored once which
also improves data consistency.

The DBMS uses its data dictionary to perform validation checks
on data entered.

Improved security

Each user can be given access rights so it can only access the
data it needs.

Data privacy is maintained.

Complex queries are easily done

Complex queries can be more easily made as the DBMS will
have a query language

Ability to create ad hoc queries

Allow concurrent access




8 Databases 2

The benefits of buying summaries with Stuvia:

Guaranteed quality through customer reviews

Guaranteed quality through customer reviews

Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.

Quick and easy check-out

Quick and easy check-out

You can quickly pay through credit card for the summaries. There is no membership needed.

Focus on what matters

Focus on what matters

Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!

Frequently asked questions

What do I get when I buy this document?

You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.

Satisfaction guarantee: how does it work?

Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.

Who am I buying these notes from?

Stuvia is a marketplace, so you are not buying this document from us, but from seller siennathompson1. Stuvia facilitates payment to the seller.

Will I be stuck with a subscription?

No, you only buy these notes for £3.49. You're not tied to anything after your purchase.

Can Stuvia be trusted?

4.6 stars on Google & Trustpilot (+1000 reviews)

84866 documents were sold in the last 30 days

Founded in 2010, the go-to place to buy revision notes and other study material for 14 years now

Start selling
£3.49
  • (0)
  Add to cart