I predict the new autonomous database will run fine on small data sets, but when you get in the terabyte range it will be terrible. The reason that it will perform poorly is that it will take forever (and it does) to run statistics. They will have to get a good Oracle DBA (dying breed) to get a diagnosis of what is wrong.
He will figure out the statistics job is the problem, because it takes to long to gather statistics on terabytes of data.
I predict that after the DBA does his handy work, the ML will make bad decisions on tuning because the database statistics used by the oracle cost based optimizer are stale. The stats will be stale because it takes too long to run them and the DBA made a work around. Performance will be dog slow.
When asked why the stats are stale... they will find out the DBA began exporting and importing stats to improve performance. They will blame the DBA and fire him. Then they the customer will complain. Oracle will go back to square one. A new stats ML package patch will come out.
Then machine learning will pick the best way to manage stats collection. It will realize that the stats take to long and then begin experimenting with alternatives. It may auto partition and select plan base lines that it loads and unloads depending on the data. With in a few days it will become so convoluted that no human can figure out what is going on.
The database will eventually flat-line and have to be rebuilt from scratch. A good old DBA will rebuild the database and turn ML off and... the new autonomous database will go quietly the way of the tuning adviser package...
But the cost of the new DBA will be higher than ever before. You will need skills as an oracle DBA, a storage expert, a cloud expert, an exadata expert and this same guy will have to know machine learning.
Looking at the cost of the unmitigated disatser running on the Oracle cloud and the ludicrous expense of the Oracle DBA... everyone will quickly get off Oracle at an accelerated rate.
You have read the prophesy December 22 2017
Easy prophesy... when history tends to repeat itself ...
Oracle Tuning Pack, an add-on pack for management of Oracle Database 11g, offers an extremely cost effective and easy-to-use solution that automates the entire application tuning process. Enhancement of SQL performance is achieved through real-time monitoring and SQL Advisors that are seamlessly integrated with the Enterprise Manager, and together provide a comprehensive solution for automating the complex and time-consuming task of application tuning.