Of course, to observe the duration of vacuum operations, we can configure thelog_autovacuum_min_durationparameter, but if there are many tables in the database, the vacuum entries in the logs might be quite numerous, making it difficult to analyze.
Using log_autovacuum_min_duration really is the best solution here. It is not very difficult to write a script to pull the information out. Yes, it can be a lot of lines if there are a lot of tables, but that's part of why it's a duration and not a toggle - you can ignore the quick-running ones. Also, the log files give you historical overview that the pg_stat views simply cannot provide, in addition to the actual details of what was vacuumed and why. All that is to say that I am not convinced we need to tweak the system views when we have the information already available in a better way.
For what it's worth, log_autovacuum_min_duration is one of the few parameters that I always recommend be turned on at the highest level (i.e. log it all). The extra log verbosity is well worth it.
