star4476=# create table test(s varchar);
CREATE TABLE
Time: 2,634 ms
star4476=# alter table test set (autovacuum_enabled = false, toast.autovacuum_enabled = false);
ALTER TABLE
Time: 0,221 ms
star4476=#
star4476=# select n_live_tup, n_dead_tup from pg_stat_user_tables where relname = 'test';
 n_live_tup | n_dead_tup
------------+------------
          0 |          0
(1 row)

Time: 12,386 ms
star4476=# select reltuples, relpages from pg_class where relname = 'test';
 reltuples | relpages
-----------+----------
         0 |        0
(1 row)

Time: 0,174 ms
star4476=# explain select * from test;
                       QUERY PLAN
---------------------------------------------------------
 Seq Scan on test  (cost=0.00..23.60 rows=1360 width=32)
(1 row)

Time: 0,141 ms
star4476=#
star4476=# insert into test select 'x:' || x.id from generate_series(1, 1000000000) as x(id);
INSERT 0 1000000000
Time: 809040,060 ms
star4476=#
star4476=# select pg_sleep(1);
 pg_sleep
----------

(1 row)

Time: 1001,441 ms
star4476=# select n_live_tup, n_dead_tup from pg_stat_user_tables where relname = 'test';
 n_live_tup | n_dead_tup
------------+------------
 1000000000 |          0
(1 row)

Time: 10,935 ms
star4476=# select reltuples, relpages from pg_class where relname = 'test';
 reltuples | relpages
-----------+----------
         0 |        0
(1 row)

Time: 0,096 ms
star4476=# explain select * from test;
                             QUERY PLAN
--------------------------------------------------------------------
 Seq Scan on test  (cost=0.00..12756526.88 rows=735121888 width=32)
(1 row)

Time: 0,078 ms
star4476=#
star4476=# delete from test;
DELETE 1000000000
Time: 482985,588 ms
star4476=#
star4476=# select pg_sleep(1);
 pg_sleep
----------

(1 row)

Time: 1001,316 ms
star4476=# select n_live_tup, n_dead_tup from pg_stat_user_tables where relname = 'test';
 n_live_tup | n_dead_tup
------------+------------
          0 | 1000000000
(1 row)

Time: 11,012 ms
star4476=# select reltuples, relpages from pg_class where relname = 'test';
 reltuples | relpages
-----------+----------
         0 |        0
(1 row)

Time: 0,115 ms
star4476=# explain select * from test;
                             QUERY PLAN
--------------------------------------------------------------------
 Seq Scan on test  (cost=0.00..12756526.88 rows=735121888 width=32)
(1 row)

Time: 0,074 ms
star4476=#
star4476=# analyze verbose test;
INFO:  analyzing "public.test"
INFO:  "test": scanned 30000 of 5405308 pages, containing 0 live rows and 5550061 dead rows; 0 rows in sample, 0 estimated total rows
ANALYZE
Time: 284,481 ms
star4476=#
star4476=# select pg_sleep(1);
 pg_sleep
----------

(1 row)

Time: 1001,279 ms
star4476=# select n_live_tup, n_dead_tup from pg_stat_user_tables where relname = 'test';
 n_live_tup | n_dead_tup
------------+------------
          0 |  999992971
(1 row)

Time: 10,833 ms
star4476=# select reltuples, relpages from pg_class where relname = 'test';
 reltuples | relpages
-----------+----------
         0 |  5405308
(1 row)

Time: 0,092 ms
star4476=# explain select * from test;
                        QUERY PLAN
-----------------------------------------------------------
 Seq Scan on test  (cost=0.00..5405308.00 rows=1 width=32)
(1 row)

Time: 0,209 ms
star4476=#
star4476=# insert into test select 'x:' || x.id from generate_series(1, 1000000000) as x(id);
INSERT 0 1000000000
Time: 804891,195 ms
star4476=#
star4476=# select pg_sleep(1);
 pg_sleep
----------

(1 row)

Time: 1001,226 ms
star4476=# select n_live_tup, n_dead_tup from pg_stat_user_tables where relname = 'test';
 n_live_tup | n_dead_tup
------------+------------
 1000000000 |  999992971
(1 row)

Time: 10,967 ms
star4476=# select reltuples, relpages from pg_class where relname = 'test';
 reltuples | relpages
-----------+----------
         0 |  5405308
(1 row)

Time: 0,115 ms
star4476=# explain select * from test;
                         QUERY PLAN
------------------------------------------------------------
 Seq Scan on test  (cost=0.00..10810615.00 rows=1 width=32)
(1 row)

Time: 0,074 ms
star4476=#
star4476=# analyze verbose test;
INFO:  analyzing "public.test"
INFO:  "test": scanned 30000 of 10810615 pages, containing 2807827 live rows and 2742296 dead rows; 30000 rows in sample, 2807827 estimated total rows
ANALYZE
Time: 415,878 ms
star4476=#
star4476=# select pg_sleep(1);
 pg_sleep
----------

(1 row)

Time: 1001,296 ms
star4476=# select n_live_tup, n_dead_tup from pg_stat_user_tables where relname = 'test';
 n_live_tup | n_dead_tup
------------+------------
    2807827 |  988196876
(1 row)

Time: 10,706 ms
star4476=# select reltuples, relpages from pg_class where relname = 'test';
  reltuples  | relpages
-------------+----------
 2.80783e+06 | 10810615
(1 row)

Time: 0,090 ms
star4476=# explain select * from test;
                            QUERY PLAN
------------------------------------------------------------------
 Seq Scan on test  (cost=0.00..10838693.27 rows=2807827 width=11)
(1 row)

Time: 0,259 ms