Some notes about Database snapshot

A database snapshot is a static, read-only copy of an existing Microsoft SQL Server database.When creating a database snapshot, you must ensure that your source database constantly and consistently
remains available. The following is a list of the most common prerequisites and limitations of
the source database:

• Database snapshots are supported only in the Enterprise version of SQL Server 2012.
• The source and the snapshot database must reside on the same SQL Server instance.
• The source database cannot be dropped, detached, or restored.
• Source database files cannot be dropped.
• Performance could be negatively affected due to increased I/O on the source. 

The syntax script to create database snapshot

CREATE DATABASE 
ON
(
NAME = ,
FILENAME = 
)
AS SNAPSHOT OF