[ttfkam]

The decision between pl/pgsql and something like plv8 isn't LOC. It's whether the solution best fits a set-oriented model or a procedural model. Both are valid, just different use cases.

There are a lot of cases where plv8 will thrash back and forth between the internals of Postgres and C and its v8 engine. These are usually the cases where set theory dominates the solution space.

On the flip side, if you're doing a lot of filter/map/reduce on large JSON payloads, plv8 is demonstrably better than pl/pgsql.

Right tool. Right job.