The United States held an election recently, and there has been some … mild controversy regarding the results. Many raised issues about this before the election itself, but what if we had used instant-runoff voting instead? More importantly, can we implement it with Postgres?
I know a lot of people watched the election results in disbelief last night, or woke up this morning and thought something like this:
There’s a bit of sad truth there. But the real problem is how we reached the point where this was even possible. The amount of incredulity on display here is actually quite shocking to anyone that was paying attention. I knew Trump had some small chance given the political environment in America right now, yet I never thought he could actually win. The reason behind that misapprehension should shock some sense into every single one of us.
Through the wonderful magic of corporate agreements, I’ve been pulled back into (hopefully temporarily) managing a small army of MySQL servers. No! Why can’t this just be a terrible nightmare?! Does anyone deserve such debasement?[caption id="attachment_1299" align="aligncenter" width="550"] Side effects of using MySQL may include…[/caption]
Hyperbole? Maybe a little. If MySQL was really that terrible, it wouldn’t be in such widespread use. However, as a Postgres DBA for so many years, I’ve come to appreciate what really sets it apart from engines and development approaches like those showcased in MySQL.
Partitioning tables in Postgres can be an extremely risky endeavor. Unfortunately on many larger systems, it’s also essentially a requirement; the maximum size of a Postgres table is 32TB. This isn’t just because converting an existing table to a series of partitions is expensive or time consuming. We must consider how the query planner will react to the partitioned version of a table. There’s also the very real risk we will (or already have) implement flaws in the trigger or constraint logic.
Tools like pg_partman or pg_pathman are great for new systems, but existing deployments require retrofitting. So what happens if we have a large warehouse that’s already using a slightly flawed partition engine? And what other concerns remain even after achieving a pristine setup?
One of the things Postgres has been “missing” for a while is logical replication based on activity replay. Until fairly recently, in order to replicate single tables from one database to another, we had to encumber the table with performance-robbing triggers coupled to a third party daemon to manage transport. Those days might finally be behind us thanks to pglogical.