What is the difference between CHAR and VARCHAR2 data types in Oracle?

In Oracle, CHAR and VARCHAR2 are both data types used to store character strings. However, there are some key differences between the two:

• CHAR: The CHAR data type stores fixed-length character strings. When you define a column with CHAR type, it will always reserve the specified length, padding the remaining spaces with blanks if the data is shorter than the specified length.
• VARCHAR2: The VARCHAR2 data type stores variable-length character strings. It only allocates the amount of storage needed for the actual data, saving space compared to CHAR. VARCHAR2 columns can hold up to 4000 bytes of data.

Choosing between CHAR and VARCHAR2 depends on the specific requirements of your data. If you have a fixed-length data format, CHAR might be more suitable. For variable-length data that can vary in size, VARCHAR2 is more efficient in terms of storage space.

It's important to note that in Oracle, both CHAR and VARCHAR2 are part of the ANSI SQL standard and are widely used in database design and development.

The Difference Between CHAR and VARCHAR2 Data Types in Oracle

In Oracle, the main difference between CHAR and VARCHAR2 data types lies in how they store character data.

CHAR Data Type

CHAR data type is fixed-length, meaning it allocates space for the maximum size specified regardless of the actual data length. For example, if a column is defined as CHAR(10) and a value 'hello' is stored in it, the remaining space will be padded with spaces to make it 10 characters long.

Focus Keyword: VARCHAR2 Data Type

VARCHAR2 data type, on the other hand, is variable-length. It only allocates storage for the actual data length plus two bytes. This means it can save storage space compared to CHAR as it does not pad the data with extra characters.

When deciding between CHAR and VARCHAR2 data types in Oracle, consider the storage requirements and whether fixed-length or variable-length is more suitable for your data storage needs.