Tip of the Day - Oracle & PostgreSQL for Developer & Administrator

Tip of the Day ( Monday, October 27, 2025 )

Precision and scale of Number data type in Oracle

In Oracle database, you can specify a fixed-point number using the form: NUMBER(p.s)

• ‘p’ is the precision which indicates the maximum number of total significant decimal digits. (From the most to the least significant digit)
• ‘s’ is the scale which indicates the number of digits from the decimal point to the least significant digit, The scale can range from -84 to 127.

Please see the image below for a better understanding.

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Tip of the Day ( Sunday, October 26, 2025 )

About VARCHAR2 data type in Oracle

VARCHAR2 – Variable length character string in the database character set. VARCHAR2 only uses as much space as needed for the stored data, making it more efficient.

Syntax: VARCHAR2 (size [BYTE | CHAR])

• size option is mandatory and defines the maximum length of the VARCHAR data type.
• Minimum size : 1 byte or character
• Maximum size : 4000 bytes or characters

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Saturday, October 25, 2025

About CHAR datatype in Oracle

CHAR is a Fixed length character strings in the Database character set. 

• Syntax : CHAR [(size [BYTE | CHAR])]
• Size is optional. Default size: 1 BYTE
• Minimum size : 1 byte, Maximum size : 2000 bytes

Example: (In a CREATE TABLE statement)

CREATE TABLE local
(
 state_code CHAR(2),   // Fixed 2 byte state code
 country_code CHAR(3), // Fixed 3 byte country code
 active CHAR           // 'Y' or 'N' - Fixed 1 byte active status. Default size
);