User-Defined Availability

---

Sometimes database availability is not defined by the database administrator. Even if the DBA can connect to the database and select against tables, users may not be having the same experience from their application.

Take the example of Horatio's Woodscrews. Due to massive transaction processing that occurs over the course of the day against the woodscrew_orders table, thousands of new rows could be added over the course of a day. When the CEO goes to check on his reports which show how many woodscrews are being sold, and to which customers, the report is creating an ad hoc SQL query against the entire table. Because of the amount of data, and the simplistic data design, these queries might not return in what the CEO envisions as a reasonable amount of time. The DBA of the company is inundated with uncomfortable calls from impatient executives wondering why the database is 'down.'

The CEO has a button on his desktop application, see, that says nothing more than woodscrew_orders_by_customer. He has no interest in hearing about how long-running queries against massive amounts of data might take a little longer than his expectations. He just wants the report to be available.

---