Tipos de dados Oracle

Tipo de dados do caractere

The length semantics of character datatypes can be measured in bytes or characters.

Byte semantics treat strings as a sequence of bytes. This is the default for character datatypes.

Character semantics treat strings as a sequence of characters. A character is technically a codepoint of the database character set.

So VARCHAR (10 Byte) has length measured in byte. VARCHAR (10 CHAR)  has length measured in character.

The default for VARCHAR is based on NLS_LENGTH_SEMANTICS parameter set in the database. By default this is set to Byte,so when we use VARCHAR(10) , it uses length measured in byte

Example

create table test  (
First_name char(6),
Last_name varchar2(10));

Tipo de dados numérico

Example

create table test  (
First_name char(6),
Last_name varchar2(10)
age number;
Salary number(10,2)
); 

Data e hora

 Example

create table test  (
First_name char(6),
Last_name varchar2(10)
age number,
Salary number(10,2),
start_date date );

Objetos grandes

Longo

desordenado