@Tom - Glad to be help. 🙂
@Jim_K - I am not sure if this can be an advantage, but to my knowledge -
Say the 1TB tape where it has backups taken each day from past 3 weeks.
(now we know that the tape's all backups are either in the compressed or uncompressed format (not both), but lets say compressed)
Now if used the FORMAT command, the tape's header part is formatted, so it does not has the clue what kind of backups previously exists (as the entire media will be invalid), so the new first backup can be in compressed or in uncompressed format. Here FORMAT can be used for making the existing tape usable for new set of backups (any format).
If used the INIT command, the tape's header is not been formatted, so it holds the details of what kind of backup it consists. Here when the backup is done even without using the COMPRESSION word the backup goes as compressed and it gets overwitten to the existing media (OR it will give the error message saying the format of the existing media and the new backup request is not matching and backup might fail). The backup always makes a default check on the HEADER section on the associated media and then act accordingly.
In the part B, if the FORMAT is used then the header details is removed and as the COMPRESS word is not mentioned so the data goes as uncompressed because the BACKUP commend could not find the details and it considers it as a new media.
In the sense of advantage
- By using FORMAT - I can say it just helps the tape to be reused for any type of backups completely.
- By using INIT - The backup needs to be continued in the same way as the previous backup format were and then reuse the entire tape's space.
Hope this helps.
The first and the hardest SQL statement I have wrote- "select * from customers" - and I was happy and felt smart.