Oracle *

There’s a dangerous illusion that “vanilla” open source is a silver bullet for enterprise systems. A real-world stress test of recent years has shown the opposite: when familiar giants like Oracle step aside, plain PostgreSQL often turns into a pumpkin under true enterprise workloads.

Mark Rivkin, Head of technical consulting at Postgres Professional, shares his personal perspective on why teams end up reinventing the wheel — adding millions of lines of code to the core — and why the future belongs to converged database systems.

Disclaimer: this article reflects the author’s independent expert opinion.

@tracefile_read_last_by_mask filemask [regexp] [ignore_regexp]
– finds last trace by filemask and filters rows by regexp and filters out rows by ignore_regexp:

Why did I write this article?

When I was preparing for Java 8 OCA and OCP I found a lot of useful articles about subjects on Habr that helped me to choose the optimal path and save a considerable amount of time.

When I started preparing for OCA Oracle Database SQL (1Z0-071) I didn’t find any materials on Habr about this matter and found there to be limited information available on the Internet. Because of this I decided to write a complete guide in order to help others who are interested in this certification to help them save time and successfully pass what I consider to be a pretty hard exam.