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* No problem, only curiosity
@ 2023-01-24 13:06 Loles <lolesft@gmail.com>
0 siblings, 1 reply; 3+ messages in thread
From: Loles @ 2023-01-24 13:06 UTC (permalink / raw)
To: pgsql-admin
Hello community!
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)
Thanks!
^ permalink raw reply [nested|flat] 3+ messages in thread
* Re: No problem, only curiosity
@ 2023-01-24 13:51 Erik Wienhold <ewie@ewie.name>
parent: Loles <lolesft@gmail.com>
0 siblings, 1 reply; 3+ messages in thread
From: Erik Wienhold @ 2023-01-24 13:51 UTC (permalink / raw)
To: Loles <lolesft@gmail.com>; pgsql-admin
> On 24/01/2023 14:06 CET Loles <lolesft@gmail.com> 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
^ permalink raw reply [nested|flat] 3+ messages in thread
* Re: No problem, only curiosity
@ 2023-01-24 13:55 Loles <lolesft@gmail.com>
parent: Erik Wienhold <ewie@ewie.name>
0 siblings, 0 replies; 3+ messages in thread
From: Loles @ 2023-01-24 13:55 UTC (permalink / raw)
To: Erik Wienhold <ewie@ewie.name>; +Cc: pgsql-admin
Oh yes.. sorry and thank you.
El mar, 24 ene 2023 a las 14:51, Erik Wienhold (<ewie@ewie.name>) escribió:
> > On 24/01/2023 14:06 CET Loles <lolesft@gmail.com> 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
>
^ permalink raw reply [nested|flat] 3+ messages in thread
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2023-01-24 13:06 No problem, only curiosity Loles <lolesft@gmail.com>
2023-01-24 13:51 ` Erik Wienhold <ewie@ewie.name>
2023-01-24 13:55 ` Loles <lolesft@gmail.com>
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