The reasons for data consistency problems that may be caused by storing snapshots.

Is the snapshot command issued until the snapshot is executed, can the disk still be written during this period of time? 

For example, when I am writing a large video file, it may take 10 minutes to write, and in the middle of writing, perform a snapshot. How does the snapshot at this time deal with the file being written, that is to say, does the data recovered from this snapshot have the file being written?

If the ORACLE database is storing in the snapshot, the database is also writing data to the disk, what is the situation? Can such a snapshot database be used?

Database data should be stored in the host cache, storage cache, and storage disk. If a snapshot is taken, is the cached data taken?

Please give me guidance!

Thanks