Oracle Tutorial Part 1 - Introduction to Database

Hello everyone, I'm going to start a tutorial series on Oracle today. Please do follow for the complete course.

Database :
It is a collection of information ( which is related ) that can be easily managed, accessed and updated. The best example for a database is the telephone directory. It can be considered as a single file consisting list of all the citizens with their names, telephone numbers and addresses.

Physical file as Database :
A field is a single unit of information. (Example : name, address, telephone no)
A record is a set of complete fields. ( each record is a telephone no )
A file is a collection of records.

Database Synonyms :
Table --> Relation
Field --> Column / Attribute
Record --> Row / Tuple / Entity

Drawbacks of Physical Databases :
Searching : searching is extremely difficult in this case. You can search for a phone no knowing the name of a person, but you cannot search for a name using the telephone no i.e. reverse searching is not possible in a physically maintained database.
Dynamic updates : New telephone numbers which are registered and the old numbers which are disconnected cannot be immediately updated.
Information sharing : The same telephone directory cannot be accessed by more than one person at the same time.
Chance of Errors : Chances of human errors like typographic are more in physical databases.
Security : If one has a telephone directory, the information is no more secured and all the data can be easily accessed.