I think the title is clear what I am going to write in your post.

This is age old problem and I want to compile the list stating advantages and disadvantages of using GUID and INT as a Primary Key or Clustered Index or Both (the usual case).

Let me start a list by suggesting one advantage and one disadvantage in each case.

INT

Advantage:

1. Numeric values (and specifically integers) are better for performance when used in joins, indexes and conditions.
2. Numeric values are easier to understand for application users if they are displayed.

Disadvantage:

1. If your table is large, it is quite possible it will run out of it and after some numeric value there will be no additional identity to use.

GUID

Advantage:

1. Unique across the server.

Disadvantage:

1. String values are not as optimal as integer values for performance when used in joins, indexes and conditions.
2. More storage space is required than INT.

Please note that I am looking to create list of all the generic comparisons. There can be special cases where the stated information is incorrect, feel free to comment on the same.

Please leave your opinion and advice in comment section. I will combine a final list and update this blog after a week. By listing your name in post, I will also give due credit.

Reference: Pinal Dave (http://blog.SQLAuthority.com)