comments in sql server, good or not good for performance?

Is it a good practice to add comments on tables and columns via sp_addextendedproperty ? Someone told me that it will slow the database and it is not worth i开发者_JAVA技巧t. What do you think ?

Yes, I think it is good practice

No, it doesn't slow performance. Why would it? Does "someone" have empirical proof or an authoritative article?

It is a great practice to comment the code. Just like coding in a front-end tool, comments are very useful for maintenance & documentation purposes.

Will it slow the "database" down? Absolutely not.

Well, let me correct myself.

Code + Inline Comments only come into play when the engine evaluates and prepares the execution plan.

So the compilation may take a very negligible time to ignore the comments, but that's about it.

Extended properties will not slow the database and there are automated help tools that will harvest the extended properties to produce documentation for you, very useful.