You can measure "bloat" in the index. It's essentially the wasted space in pages.
You can also have bloat in the heap for the same reasons.
You may also want to cluster if your pg_stat.correlation is low since that indicates your heap isn't in the same order as your index anymore. pg_repack can do all of this without blocking, but you can reindex just an index concurrently on version >= 12.
You can also have bloat in the heap for the same reasons.
You may also want to cluster if your pg_stat.correlation is low since that indicates your heap isn't in the same order as your index anymore. pg_repack can do all of this without blocking, but you can reindex just an index concurrently on version >= 12.
https://wiki.postgresql.org/wiki/Show_database_bloat