How Do Precision and Scale Define Decimal Data Types in Databases?

Understanding Precision and Scale in Database Numbers

Databases often utilize decimal data types to store numerical values with varying precision and scale requirements. In the context of a database column, the precision and scale parameters are represented as decimal(numeric precision, numeric scale).

Consider the example of a column declared as decimal(5,2). This notation indicates that the column supports:

• Numeric Precision: The maximum number of digits allowed in the value. In this case, it is 5, meaning that the value can have up to 5 digits in total.
• Numeric Scale: The maximum number of digits after the decimal point. With a scale of 2, the value can have up to 2 decimal places.

Hence, the correct interpretation of decimal(5,2) is that it can accommodate values with a maximum of 5 digits before the decimal point and 2 digits after the decimal point (e.g., 12345.12). This is different from the common misconception of it representing a decimal with 5 total digits and 2 decimal places (e.g., 123.45).

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