2. What is database ?
a collection of data or information that is
organized so that its contents can easily be
accessed, managed, and updated.
3. Type of database
Manual database
Computerized database
What is the difference
between manual database
and computerized
database?
4. Manual database
Lists created on stone, metal or paper are
called manual database.
Example: List students’ mark. The list
consists two columns, NAME and MARKS.
Teacher fill in the names and marks for each
subject according to level : year 7, year 8 etc.
These paper files are then stored in filling
cabinet.
6. Manual database
Disadvantages :
Accesing file and updating is very time
consuming. for example when data needs
to be retreived or updated, the user has to
search through file to locate them
physically.
Take up a lot of space since data has to be
stored files.
8. Computerized database
Advantages :
Store information only once since most database
software allows you to access information from
several files.
Validation checks may be made on the data so
that there will be fewer errors in the data.
Files can be linked together, which means that if
you update one of the files, all the other files that
depend on the same information will automatically
be updated.
Access information is quickly.
9. Computerized database
Disadvantages :
If the computer breaks down, you are not
able to access the details.
It is easy to copy computer files.
Training is needed to use system so that this
takes time and cost money
Database may be corrupted / infected.
Some database complicated to us.
10. Parts of database
Databases are organized in files which consist
of a series of records which in turn consist of a
series of fields.
Once your
understood this,
you will be well on
the way to
understanding
database.
11. Parts of database
Files - a collection of data or information that
has been given a name.
13. Parts of database
Fields – records contains a number of fields. (
each item in a record )
14. Parts of database : Scenario
1. Information of all student s in a
school could be save as student file
2. Student record card - record
3. Student number, forename, form,
DOB – field name
15. Two main types of database
flat file database
relational database
16. Two main types of database
Flat file database Relational database
Use on personal computer. Used a lot in large organisations.
Store data in one file at a time
and this must store all the data.
Store data in separate tables and
files.
(have links/ relationships which
allow data from another file to be
shown, used and edited but not
copy in a current file. So that
whenever the values the other file
change, the data displayed in the
current file also changes.
Not suitable for large database
because they can be slow, have
large file size and use a lot of
memory.
