Quick Answer : Do not use GUID as primary key
As Kimberly Tripp - the Queen of Indexing - and others have stated a great many times - a GUID as the clustering key isn't optimal, since due to its randomness, it will lead to massive page and index fragmentation and to generally bad performance.
<a target="_blank" href="https://www.sqlskills.com/blogs/kimberly/guids-as-primary-keys-andor-the-clustering-key/">https://www.sqlskills.com/blogs/kimberly/guids-as-primary-keys-andor-the-clustering-key/</a>
<a target="_blank" href="https://stackoverflow.com/questions/11938044/what-are-the-best-practices-for-using-a-guid-as-a-primary-key-specifically-rega">https://stackoverflow.com/questions/11938044/what-are-the-best-practices-for-using-a-guid-as-a-primary-key-specifically-rega</a>

Quick Answer : **Do not use** GUID as primary key

As Kimberly Tripp - the Queen of Indexing - and others have stated a great many times - a GUID as the clustering key isn't optimal, since due to its **randomness**, it will lead to massive page and index **fragmentation** and to generally bad performance.

[https://www.sqlskills.com/blogs/kimberly/guids-as-primary-keys-andor-the-clustering-key/](https://www.sqlskills.com/blogs/kimberly/guids-as-primary-keys-andor-the-clustering-key/)

[https://stackoverflow.com/questions/11938044/what-are-the-best-practices-for-using-a-guid-as-a-primary-key-specifically-rega](https://stackoverflow.com/questions/11938044/what-are-the-best-practices-for-using-a-guid-as-a-primary-key-specifically-rega)

A developer's diary

A developer's diary

Performance of GUID as primary key ?