I was doing an upgrade of one of our PG (9.6.11 to 11.9) database and came across the question that what is reason PostgreSQL is not doing copy of stats and we have to analyze right after upgrade. There are two situations where this will help when we use this DB as our enterprise database:
1. If DB is in magnitude of hundreds of TB and we have to do analyze it might take several hours before we handover this to application services.
2. We are loosing critical information like most common values and most common freqs because these values are populated over time when many-many sessions hit table and queries with different values of a column.