In the previous post, you could see how to create set-returning functions that returns several rows of a table and we returned rows consisting of the timestamp, the metric, and two JSONB values: one for the tags and one for the fields. There were, however, no coverage of what JSONB is, how it differs from JSON, and how to construct them in your code. This post is going to answer those questions.
In the previous post you could see how to create a background worker that received data over a socket as well as how to spawn a new background worker. In this post you will see how to write a simple parser for the InfluxDB Line Protocol and also get an introduction into PostgreSQL Memory Contexts and the Set-Returning Function (SRF) interface and learn how to write a function that returns multiple tuples.