About sequences Sequences are used to generate artificial numeric primary key columns for tables. A sequence provides a “new ID” that is guaranteed to be unique, even if many database sessions are using the sequence at the same time. Sequences are not transaction safe, because they are not supposed to block the caller. That is […]

“How does the PostgreSQL optimizer handle views?” or “Are views good or bad?” I assume that every database consultant and every SQL performance expert has heard this kind of question already. Given the fact that views are a really essential feature of SQL, it makes sense to take a closer look at the topic in […]

Pgbench is a very well-known and handy built-in tool that Postgres DBAs can use for quick performance benchmarking. Its main functionality/flow is super simple, but it also has some great optional features, like running custom scripts and specifying different probabilities for them. One can also use bash commands to fill query variables for example. But […]

Is there a single significantly large and important database in the world, which does not suffer from performance problems once in a while? I bet that there are not too many. Therefore, every DBA (database administrator) in charge of PostgreSQL should know, how to track down potential performance problems to figure out, what is really […]

Many people keep asking about index scans in PostgreSQL. This blog is meant to be a basic introduction to the topic because many people do not seem to be aware of what the optimizer does, when a single query is processed. I decided to give a brief introduction showing, how a table can be accessed […]

The last couple of weeks I’ve had the chance to work on our Open Source PostgreSQL monitoring tool called pgwatch2 and implemented some stuff that was in the queue. Changes include only a couple of fixes and a lot of new features… so hell, I’m calling it “Feature Pack 3″… as we’ve had some bigger […]