Monday, January 22

Author: Simon Riggs

PostgreSQL Meltdown

Simon's PlanetPostgreSQL
Spectre and Meltdown have caused severe alarm in recent days. You may have read about up to 30% impact on PostgreSQL databases, which I believe to be overstated because of misunderstandings in the media. Let's dig into this in more detail. TL;DR Summary: no PostgreSQL patch required, -7% performance hit In response to these new security threats various OS patches have been released. Various authors have published benchmarks around these and they have, in some cases, stated worst-case measurements as impact measurements. For example: stating a 30% hit when, in fact, we are seeing a 7% hit on a busy server. Regrettably, it looks to me like some people outside the PostgreSQL community have spread this news as a problem for PostgreSQL, without clearly stating the workload measured, or (more…)

PostgreSQL is the DBMS of the Year 2017

Simon's PlanetPostgreSQL
The annual DBEngines ranking have just been updated, with PostgreSQL winning the "DBMS of the Year 2017" award. https://db-engines.com/en/blog_post/76 PostgreSQL was a runner up last year. https://db-engines.com/en/blog_post/67 So across the year, we have made more gains in popularity than all other databases. Looking at the detail we see that all of the other 4 databases that make up the Top 5 have reduced in popularity from last year. PostgreSQL has gone up, others have gone down. What's even more interesting, is that PostgreSQL is the only database in the top 5 systems that has increased steadily over the last 4 years. Slow, steady progress. The word is out! Why is that? PostgreSQL is multi-talented, offering relational features when needed, as well as JSON features for (more…)

How long does it take to change your mind?

2ndQuadrant, Simon's PlanetPostgreSQL
You're clever, which means you're mostly right about things. But everybody is wrong sometime, so how long does it take for you to change your mind? People don't often change their minds quickly. A snap answer is always whatever you were thinking currently. If it was a No, you say No. If it was a Yes, you say Yes. If you answer too quickly you can't possibly have taken in what was being said to you. Can you change your mind? "When the facts change, I change my mind. What do you do, sir?", often misattributed to John Maynard Keynes. https://quoteinvestigator.com/2011/07/22/keynes-change-mind/ For Humans, changing your mind based on new information takes days or months. If you have emotional objections, it can take months or years. If anyone has research on that, I'd be interested (more…)

Oracle High Availability concepts in PostgreSQL

2ndQuadrant, Barman, PostgreSQL, Simon's PlanetPostgreSQL
Sometimes people ask about certain Oracle High Availability features and whether they exist in PostgreSQL. In most cases, very similar features exist. The reason for the similarity is that PostgreSQL and Oracle have very similar architectures and so the mechanisms to protect data have also developed along the same lines. For example, Oracle Data Guard is streaming replication of the transaction log, so is very similar in concept to physical streaming replication in PostgreSQL. Active Data Guard is where Oracle users can run queries on a standby server, which again is similar in concept to Hot Standby. Oracle RAC? You don't really need Oracle RAC. Or at least qualified Oracle experts tell me so and my own hands on experience confirms that. Not least because disaster recovery for (more…)

Why PostgreSQL is better than MySQL

Simon's PlanetPostgreSQL
Someone recently tweeted about the fantastic news that MySQL fixed a bug. Now in my world, bugs get fixed quickly and well. Bugs happen and they need to be fixed. It never occurred to me that we should ever tweet or blog about the fixing of a bug. I guess I assume it's just quality: bugs get fixed, no drama - people depend upon us to do just that so that the (literally) millions of PostgreSQL servers out there run well. That's our job and I'm happy and proud to do that job alongside my colleagues at 2ndQuadrant and my colleagues in other PostgreSQL companies and in the wider community. So the bug in question was "number 199"... check this out http://lefred.be/content/bye-bye-bug-199/ It's always been a big argument in the PostgreSQL community about whether we need a bug tracker (more…)

PG10 at the London PostgreSQL Meetup

Simon's PlanetPostgreSQL
We recently hosted the London PostgreSQL Meetup at a new location in Covent Garden. Room was great and its about 100m from Leicester Square tube, so very centrally located and easy to get to. https://www.meetup.com/London-PostgreSQL-Meetup-Group/ I've been the organizer of the group for more than 6 years now, in my role as the PostgreSQL Project's UK Press representative, though a few others have also helped out, principally Bart Swedrowski, though now also Sam Marshall. Anybody interested in PostgreSQL is welcome to come along and we have many speakers from a variety of companies and types of company. Please come along and join in with the other 849 members. At our recent meeting we discussed all the new features of PostgreSQL 10. Lots of interest in the new SCRAM authentication (more…)

News and Roadmap for BDR (Multi-master PostgreSQL)

2ndQuadrant, Simon's PlanetPostgreSQL
Postgres-BDR is an open source project from 2ndQuadrant that provides multi-master features for PostgreSQL. We have pursued a joint strategy of providing both working code available now and also submitting the features into core PostgreSQL. Postgres-BDR 1.0 runs on a variant distro of PG9.4. This is in Production now and receives regular maintenance and security updates. 2ndQuadrant will support this until 9.4 End of Life in December 2019. One of the greatest achievements to come out of our work on BDR is the logical replication technology. Our engineers spent a considerable amount of energy to contribute the tech to PostgreSQL core and I feel especially proud that this is a headline feature of the upcoming PG10 release. And Now BDR 2.0 …  BDR 2.0 runs on community PG9.6 as (more…)

PostgreSQL Popularity Continues to Grow!

Simon's PlanetPostgreSQL
Some years ago, I prophesized that PostgreSQL would win in the end, and that we would be able to tell because there would be "Microsoft PostgreSQL". I am happy to report that has now happened. Microsoft PostgreSQL database service on Azure was announced recently. Of course, that was just a metaphor for "a.n.other big company", I'm not signalling MS as requiring special attention here, in fact they have been the last to do this. That means PostgreSQL database services are now available from all of the main cloud service providers: Amazon, Google, IBM and Microsoft. Yay! We have achieved 100% breakthrough in terms of cloud adoption - everyone recognizes now that PostgreSQL is big and adoption is accelerating. PostgreSQL is now used in UK and US governments, see UK (http://www. (more…)

PgDay Paris 2017

2ndQuadrant, Simon's PlanetPostgreSQL
Great conference! Paris is a great venue for travellers across Europe and worldwide. PgDay Paris 2017 was held in English and attracted a wide audience from many other countries: UK, NL, CH, BE, US, SE - and that was just the people I spoke to. Je suis desolee ne parler ou ecrit pas en francais. Je suis un developpeur seulement. I spoke in English about the new features in PostgreSQL 10 regarding Replication & Recovery. All very well received by a large technical audience. Logical replication, physical replication improvements, quorum commit, replication lag measurement and a ton of fine detailed improvements. No slides, sorry. Come to the conferences! Meet people, hear their stories and share yours. I travelled to Paris through London on a day of public murders that made news (more…)

Dataloss at GitLab

2ndQuadrant, Simon's PlanetPostgreSQL
GitLab, thanks for using PostgreSQL 9.6 and its replication and backup facilities. We're sorry that you lost your database: https://about.gitlab.com/2017/02/01/gitlab-dot-com-database-incident/ Thank you for posting this publicly to allow us to comment on this for your postmortem analysis. I'm very happy that you monitor Replication Lag, that is good. Replication lag of 4GB is at times normal, so shouldn't have caused major concern. I've recently fixed a bug in replication that caused replication to hang in some cases for up to a minute; we released a public fix to that and it will be included in the next maintenance release of PostgreSQL 9.6. It's not certain that the bug was hit and, if it was, whether that was enough to cause the slow down noted. The openness of your response (more…)