Error logging in SQL Server 2012 - sql

Question

I guess by default only error with severity 20-25 will gets logged into SQL Server error log file. How can I change the config to log even other errors which are less severity? Or where I can find less severe errors getting logged in SQL Server? I am interested in errors such as
could not find stored procedure spName
etc.

Answer 1

I extracted the following block from this article, which would be a good starting point to explore the SQL Server error log config changes.
Logging Errors
SQL Server Agent takes these errors from the error log, so if follows that the errors must be logged in the first place. There is no way of attaching alerts to errors that aren't logged. All error messages with a severity level from 19 through 25 are written to the error log automatically.
So, what if you want to log information messages, or messages of low severity? If you wish to have an alert on any errors that are of a severity less that 19, then you have to modify their entry in the sysmessages table to set them to be always logged.
You do this using sp_alterMessage with the WITH_LOG option to set the dLevel column to 128 . If a message has been altered to be WITH_LOG, it is always subsequently written to the application log, however the error happens.
Even if RAISERROR is executed without the WITH LOG option, the error that you have altered is written to the application log, and is therefore spotted by the alert. There are good reasons for wanting to do this, as it will then log, and optionally alert you to, syntax errors that are normally seen only by the end-user.
You can force any error that is triggered programmatically to be written to the error log by using the WITH LOG parameter with the RAISERROR command. So, with a user-defined error severity (9) you can log an incident, cause an alert to be fired, which in turn emails someone, or runs a job, simply by using RAISERROR.
Naturally, because the job that responds to the alert can be run by the Agent under a different User, you do not need to assign unsafe permissions to the ordinary user. You can use xp_LogEvent if, as is likely, you do not want the user to see the error. (Only the Raiserror call can utilize the 'PrintF' formatting placeholders in the error messages, so logging the error with a formatted message using xp_logevent results in a literal recording of the message, string format identifiers and all.)
I would recommend to refer the original article for more/detailed information on this.
Please follow this link to find out more on severities.