> On 24/01/2023 14:06 CET Loles <lolesft@xxxxxxxxx> wrote: > > Does anyone know why I am getting a result less than 2 million rows in this > example? > > postgres=# create table test_n_tup_live (id serial); > CREATE TABLE > > postgres=# insert into test_n_tup_live select generate_series(1,1000000); > INSERT 0 1000000 > > postgres=# analyze test_n_tup_live ; > ANALYZE > > postgres=# select n_live_tup, n_dead_tup from pg_stat_user_tables where relname = 'test_n_tup_live'; > > n_live_tup | n_dead_tup > ------------+------------ > 1000000 | 0 > (1 fila) > > postgres=# update test_n_tup_live set id = id + 1; > UPDATE 1000000 > > postgres=# insert into test_n_tup_live select generate_series(1,1000000); > INSERT 0 1000000 > > postgres=# select n_live_tup, n_dead_tup from pg_stat_user_tables where relname = 'test_n_tup_live'; > n_live_tup | n_dead_tup > ------------+------------ > 2000000 | 1000000 > (1 fila) > > postgres=# vacuum test_n_tup_live; > VACUUM > > postgres=# select n_live_tup, n_dead_tup from pg_stat_user_tables where relname = 'test_n_tup_live'; > > n_live_tup | n_dead_tup > ------------+------------ > 1999925 | 0 > (1 fila) Both numbers are estimates: https://www.postgresql.org/docs/current/monitoring-stats.html#MONITORING-PG-STAT-ALL-TABLES-VIEW -- Erik
