Routine analyze of single column prevents standard autoanalyze from running at all

Hi.

I'm routinely bulk inserting data to a PostgreSQL table and then 
analyzing a single column of the table, because it contains data which 
significantly changes histogram of this column values - for example 
something like adding rows with "todo=true" column, when all rows before 
bulk insert have "todo=false".

This column has rather small "statistics" value, so analyze of it is 
fairly fast, which is important as I'm doing it often and also in 
parallel (and analyze blocks - only one can run at the time). The full 
analyze of this large table would take a lot of time (20 times more 
actually), and I can't perform it after each bulk insert.

But I've noticed that a standard automatic analyze, which should work in 
background, never runs. I've noticed that this fast analyze of one 
column resets pg_stat_user_tables(n_mod_since_analyze) counter.

I suppose that the decision to analyze the whole table is based on these 
values from pg_stat_user_tables and autovacuum_analyze_threshold and 
autovacuum_analyze_scale_factor settings. And in this case this highly 
updated table never reaches these values.

I suppose this is a bug - an analyze, which does not analyze all 
columns, should not reset pg_stat_user_tables(n_mod_since_analyze). What 
do you think?

-- 
Tomasz "Tometzky" Ostrowski