U128: Division by zero

Example Postgres Log Output:

ERROR: division by zero
STATEMENT: SELECT 1/0

Explanation:

Whilst executing the statement, Postgres had to perform a division by zero, which is not allowed.

Note that this applies to both integer divisions by zero (1 / 0) as well as floating point divisions by zero (1 / 0.0).

Often this occurs due to a value thats returned from a table, so it may be unclear at first where the problematic zero is coming from.

Recommended Action:

In simple cases, the problematic expression can simply be removed. However that may often prove difficult, especially when the source data is user controlled.

One way to resolve this issue on user generated data, is to utilize NULLIF like this:

SELECT 1.0 / NULLIF(column_that_may_be_zero, 0)

This will return the result of the division in cases where the column is not zero, and return NULL in the cases where it is zero, instead of erroring out.

Learn More:

• Postgres Documentation: SQL Syntax - Value Expressions / Expression Evaluation Rules
• Postgres Documentation: Functions and Operators - Conditional Expressions / NULLIF