Journey of a DBA from Oracle to PostgreSQL
Rajni Baliyan, DBA I Ashnik
In my 4 years of IT experience as an Oracle DBA, I have been involved in many projects, learnt varied new technologies and added many certifications to my pool. But for reasons best known to me, I had to relocate to Singapore. And soon after, I got a call from Ashnik. They had an opening for a DB Consultant, though for PostgreSQL Database.
Somehow I was not comfortable with the idea of switching to another database. But again, here was a chance to learn new technologies and hence I accepted the offer, mainly as a challenge.
So here was my big task – learning a whole new database and its features. It somehow amazed me that this really was no task. Instead of unlearning Oracle and learning PostgreSQL, I simply learnt PostgreSQL by relating concepts in context of Oracle features. I figured out that most of the fundamentals and features do not change when one transitions from Oracle to PostgreSQL.
And to think of it, Oracle had surprisingly been so synonymous with RDBMS. Not the most correct notion. Considering how databases like PostgreSQL offer almost all the widely used features of Oracle or other propreitory databases.
PostgreSQL has all the core RDBMS features like-
• WAL files, which I used to call as ‘redo log’ file of PostgreSQL ensures reliability
• MVCC helps avoid lockin contention, similar to UNDO tablespace
• Shared buffers boosts the read performance the same way as database buffer cache in SGA
• Streaming Replication is very much like Oracle’s Dataguard
The fundamentals don’t change only the implementation does. As long as we understand the concepts of why Oracle has SGA, PGA or what it does with UNDO tablespace, the transition to PostgreSQL is going to be a walk in the park. And I proved it quite literally, by acquiring a PostgreSQL Associate certificate in just 3 months of starting work.
Being an open source RDBMS, PostgreSQL is open to adopt new features according to the needs of the market. Its NoSQL and JSON features are a testimony to this. Probably why, within just a few months of my encounter with it, I can now assuredly say that PostgreSQL is as good as Oracle and continues to evolve to get better and perform better.
No wonder, PostgreSQL is being considered the real alternative to organizations who are looking to move out of dated, proprietary databases.