About a year ago the PostgreSQL community discovered that fsync (on Linux and some BSD systems) may not work the way we always thought it is, with possibly disastrous consequences for data durability/consistency (which is something the PostgreSQL community really values).
PostgreSQL is emerging as the standard destination for database migrations from proprietary databases. As a consequence, there is an increase in demand for database side code migration and associated performance troubleshooting. One might be able to trace the latency to a plsql function, but explaining what happens within a function could be a difficult question. Things get messier when you know the function call is taking time, but within that function there are calls to other functions as part of its body. It is a very challenging question to identify which line inside a function—or block of code—is causing the slowness. In order to answer such questions, we need to know how much time an execution spends on each line or block of code. The plprofiler project provides great tooling and extensions to address such questions.
Braintree Payments uses PostgreSQL as its primary datastore. We rely heavily on the data safety and consistency guarantees a traditional relational database offers us, but these guarantees come with certain operational difficulties. To make things even more interesting, we allow zero scheduled functional downtime for our main payments processing services.
Several years ago we published a blog post detailing some of the things we had learned about how to safely run DDL (data definition language) operations without interrupting our production API traffic.
Since that time PostgreSQL has gone through quite a few major upgrade cycles — several of which have added improved support for concurrent DDL. We’ve also further refined our processes. Given how much has changed, we figured it was time for a blog post redux.
PostgreSQL is the database management system that gained more popularity in our DB-Engines Ranking within the last year than any of the other 343 monitored systems.
We thus declare PostgreSQL as the DBMS of the Year 2018.