K201%–%Computers%In%Business%
“Database%Processing”%
%
v What%Is%the%Purpose%of%a%Database?%
Ø The%purpose%is%to%keep%track%of%things.%
Ø Lists%of%data%involving%a%single%theme%can%be%stored%in%a%spreadsheet;%lists%
that%involve%data%with%multiple%themes%require%a%database.%
v What%is%a%Database?%
Ø DatabaseJ%is%a%selfJdescribing%collection%of%integrated%records.%%
Ø Bytes%are%grouped%into%columns,%which%are%also%called%fields.%
Ø A%group%of%similar%rows%or%records%is%called%a%table%or%a%file.%
Ø A%database%is%a%collection%of%tables%plus%relationships%among%the%rows%in%
those%tables,%plus%special%data,%called%metadata,%that%describes%the%structure%
of%the%database.%
Ø What%Are%Relationships%Among%Rows?%
§ Primary%KeyJ%is%a%column%or%group%of%columns%that%identifies%a%unique%
row%in%a%table.%Every%table%must%have%a%key.%
§ Relational%DatabasesJ%databases%that%carry%their%data%in%the%form%of%tables%
and%that%represent%relationships%using%foreign%keys.%%
Ø MetadataJ%are%data%that%describe%data.%
§ The%presence%of%metadata%makes%databases%much%more%useful.%Because%of%
metadata,%no%one%needs%to%guess,%remember,%or%even%record%what%is%in%the%
database.%To%find%out%what%a%database%contains,%we%just%look%at%the%
metadata%inside%the%database.%%
v What%Are%the%Components%of%a%Database%Application%System?%
