Progress
Database Administration
Guide and Reference


Example 1: Low Availability Requirements

The database administrators at site A have determined the following availability requirements. Table 8–1 provides examples.

Table 8–1: Sample Low Availability Requirements 
Question
Answer
Recovery Technique
How many committed transactions can you afford to lose?
1 week of transactions
Perform weekly backups.
How long can the application be offline while you perform scheduled maintenance?
8 hours per day
Perform weekly backups offline.
How long can you spend recovering if the database becomes unavailable?
24 hours
Keep a full backup and any number of incrementals or AI files.
Must distributed transactions occur consistently across databases?
No
Do not implement two-phase commit.

Given these requirements, the database administrators perform a full offline backup every Monday at 5 PM. Incrementals are not required because the site can afford to lose one week of transactions, and full backups are performed weekly. The backup is tested Tuesday at 5 PM using disk space reserved for that purpose.


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