Scaling a data-tier requires multiple concurrent database connections that are all vying for read and write access of the same data. In order to cater to this complex demand, PostgreSQL implements a concurrency method known as Multi Version Concurrency Control, or MVCC. By understating MVCC, you will be able to take advantage of advanced features such as transactional memory, atomic data isolation, and point in time consistent views.
This presentation will show you how MVCC works in both a theoretical and practical level. Furthermore, you will learn how to optimize common tasks such as database writes, vacuuming, and index maintenance. Afterwards, you will have a fundamental understanding on how PostgreSQL operates on your data.
Key points discussed:
* MVCC; what is really happening when I write data.
* Vacuuming; why it is needed and what is really going on.
* Transactions; much more then just an undo button.
* Isolation levels; seeing only the data you want to see.
* Locking; ensure writes happen in the order you choose.
* Cursors; how to stream chronologically correct data more efficiency.
SQL examples given during the presentation are available here: http://www.reactive.io/academy/presentations/postgresql/mvcc/mvcc-examples.zip