Good or bad to have buffer gets

Question

Is it good to have high buffer gets?
In the manuals it seems they say it is not good ...

Answer 1

There is not a query, application, database table or forum that can answer this question. You might see a statement that takes 10 hours to run, performs 42 billion consistent reads and 42 million disk reads...and it is running just fine. There might be a statement that takes 1 minute to run, performs 1000 consistent reads and no disk reads that is the worst performing sql in the application.
Before you decide that I am out of my mind...consider...
The first statement is an overnight batch job that performs an ETL process for the data warehouse. As long as it finishes by 7am the next morning, it does not matter how fast it runs (no one logs in to the system until 8am).
The second statement retrieves the customer account information that is used hundreds of thousands of times during the day by the sales force. I know that I would be an unhappy customer if I had to wait 1 minute every time I called in to place an order.
The only way to find the worst performing sql is to talk to the users and business, have them tell you what their important processes are and how they are impacted by response time.
There is nothing worse than spending hours tuning a sql statement that did not need to be tuned!
Regards,
Daniel Fink