Robert M. Haas

Vice President, Chief Database Architect, EDB

Robert Haas is a PostgreSQL major contributor and committer. PostgreSQL features which he has authored or coauthored include unlogged tables, fast-path locking, index-only scans, and parallel query. PostgreSQL features written by others which he has reviewed and committed include table partitioning, logical decoding, event triggers, and foreign tables. He works at EnterpriseDB as VP, Chief Database Scientist.

Prior to working at EnterpriseDB, Robert worked as a web application developer for almost 10 years. He first became interested in PostgreSQL development after running up against limitations of the PostgreSQL query optimizer during one of those jobs, specifically the inability of the optimizer to consider join removal. At EnterpriseDB, he has worked mostly on PostgreSQL, but also at times as a member of the support organization, and at other times on EnterpriseDB's Advanced Server, Backup and Recovery Tool, and Postgres Enterprise Manager products.

Read Blogs

The State of VACUUM

In a recent blog post, I talked about why every system that implements MVCC needs some scheme for removing old row versions, and how VACUUM meets that need for PostgreSQL. In this post, I’d like to examine the history of VACUUM improvements in recent years, the state of VACUUM as it exists in PostgreSQL today, and how it might be improved in the future. When I first began using PostgreSQL...

MVCC and VACUUM

Experienced PostgreSQL users and developers rattle off the terms “MVCC” and “VACUUM” as if everyone should know what they are and how they work, but in fact many people don’t. This blog post is my attempt to explain what MVCC is and why PostgreSQL uses it, what VACUUM is and how it works, and why we need VACUUM to implement MVCC. In addition, I’ll include a few useful links for further reading for...

PostgreSQL's Hash Indexes Are Now Cool

Since I just committed the last pending patch to improve hash indexes to PostgreSQL 11, and since most of the improvements to hash indexes were committed to PostgreSQL 10 which is expected to be released next week, it seems like a good time for a brief review of all the work that has been done over the last 18 months or so. Prior to version 10, hash indexes didn't perform well under concurrency...
Business Transformation

Who Contributes to PostgreSQL Development?

In a talk which I gave at PGCONF.IN and, in a shorter version, at PGCONF.US, I had a few slides on who contributes to PostgreSQL development.

New Features Coming in PostgreSQL 10

The list of new features coming in PostgreSQL 10 is extremely impressive. I've been involved in the PostgreSQL project since the 8.4 release cycle (2008-2009), and I've never seen anything like this. Many people have already blogged about these features elsewhere; my purpose here is just to bring together a list of the features that, in my opinion, are the biggest new things that we can expect to...

Parallel Query v2

A recent Twitter poll asked What is your favorite upcoming feature of PostgreSQL V10? In this admittedly unscientific survey, "better parallelism" (37%) beat out "logical replication" (32%) and "native partitioning" (31%). I think it's fruitless to argue about which of those features is actually most important; the real point is that all of those are amazing features, and PostgreSQL 10 is on track...
EDB Labs

Uber's Move Away from PostgreSQL

Last week, a blog post by an Uber engineer explained why Uber chose to move from PostgreSQL to MySQL. This article was widely reported and discussed within the PostgreSQL community, with many users and developers expressing the clear sentiment that Uber had indeed touched on some areas where PostgreSQL has room for improvement. I share that sentiment. I believe that PostgreSQL is a very good database, but I also believe there are plenty of things about it that can be improved.
EDB Labs

Corporate Giving: EDB’s Contributions to PostgreSQL

There is an important difference between the open source PostgreSQL community and many other open source communities – it is not controlled by a single company that can dictate whether others can contribute.
EDB Labs

PostgreSQL Past, Present, and Future: Moving The Goalposts

It's nice to see that PostgreSQL 9.5 is finally released! There are a number of blog posts out about that already, not to mention stories in InfoWorld, V3, and a host of other publications.
EDB Labs

Parallel Sequential Scan is Committed!

I previously suggested that we might be able to get parallel sequential scan committed to PostgreSQL 9.5. That did not happen. However, I'm pleased to report that I've just committed the first version of parallel sequential scan to PostgreSQL's master branch, with a view toward having it included in the upcoming PostgreSQL 9.6 release.