Why do many SQL Server severity 10 errors actually seem severe?

Question

BOL states that SQL Server level 10 messages are "Informational messages that return status information or report errors that are not severe."

However these errors seem severe and not informational:

• 2540 - The system cannot self repair this error.
• 2745 - Process ID %d has raised user error %d, severity %d. SQL Server is terminating this process.
• 3606 - Arithmetic overflow occurred.
• 3607 - Division by zero occurred.

These are just a few of the ones that seem more than just information. They were taken using the following query:

SELECT
message_id,
language_id,
severity,
is_event_logged,
text
FROM sys.messages
WHERE 
language_id = 1033
AND
severity = 10

Why do many SQL Server severity 10 errors actually seem severe?

Answer 1

Severity can be subjective, in your examples,
- 3606 - Arithmetic overflow occurred.
- 3607 - Division by zero occurred.

Well, these may mean ok to you but to the server, this might snowballed into something severe up to your App's business logic.

Nevertheless, I do agree that some/a lot of the messages (severity aside) are not clear/vaue/ambiguous.

Answer 2

The severity in sys.messages is not the actual severity they are raised with.