On: We saved $50k/year with a Go microservice coded in...

[zaarn]

JSONB columns should behave just like any datatype with a GIN index in the recent releases, to my knowledge.

Still, a JSON column will arguably be faster than a pure KV table since you can more efficiently query it, especially any non-JSON columns.

[ptman → zaarn]

IIRC JSONB still has problem with index statistics

So values in JSONB columns can be indexed nicely, but the statistics can be much worse than for non-JSONB columns, which can lead the query planner astray.