Can anyone confirm that the "avg_width" reported in the pg_stats is the avg_width not including any null rows?
ie if a field had:
avg_width: 6 null_frac: 0.5
Then - 50% of the rows would be empty for this field - The other 50% of the rows would have data with an avg_width of 6 bytes? (according to the sampled data at least)
