How to log PostgreSQL queries?

Postgresql Problem Overview

How to enable logging of all SQL executed by PostgreSQL 8.3?

Edited (more info) I changed these lines :

log_directory = 'pg_log'					
log_filename = 'postgresql-%Y-%m-%d_%H%M%S.log'
log_statement = 'all'

And restart PostgreSQL service... but no log was created... I'm using Windows Server 2003.

Any ideas?

Postgresql Solutions

Solution 1 - Postgresql

In your data/postgresql.conf file, change the log_statement setting to 'all'.

Edit

Looking at your new information, I'd say there may be a few other settings to verify:

make sure you have turned on the log_destination variable
make sure you turn on the logging_collector
also make sure that the log_directory directory already exists inside of the data directory, and that the postgres user can write to it.

Solution 2 - Postgresql

Edit your /etc/postgresql/9.3/main/postgresql.conf, and change the lines as follows.

Note: If you didn't find the postgresql.conf file, then just type $locate postgresql.conf in a terminal

#log_directory = 'pg_log' to log_directory = 'pg_log'
#log_filename = 'postgresql-%Y-%m-%d_%H%M%S.log' to log_filename = 'postgresql-%Y-%m-%d_%H%M%S.log'
#log_statement = 'none' to log_statement = 'all'
#logging_collector = off to logging_collector = on
Optional: SELECT set_config('log_statement', 'all', true);
sudo /etc/init.d/postgresql restart or sudo service postgresql restart
Fire query in postgresql select 2+2
Find current log in /var/lib/pgsql/9.2/data/pg_log/

The log files tend to grow a lot over a time, and might kill your machine. For your safety, write a bash script that'll delete logs and restart postgresql server.

Thanks @paul , @Jarret Hardie , @Zoltán , @Rix Beck , @Latif Premani

Solution 3 - Postgresql

FYI: The other solutions will only log statements from the default database—usually postgres—to log others; start with their solution; then:

ALTER DATABASE your_database_name
SET log_statement = 'all';

Ref: https://serverfault.com/a/376888 / log_statement

Solution 4 - Postgresql

SELECT set_config('log_statement', 'all', true);

With a corresponding user right may use the query above after connect. This will affect logging until session ends.

Solution 5 - Postgresql

You also need add these lines in PostgreSQL and restart the server:

log_directory = 'pg_log'    				
log_filename = 'postgresql-dateformat.log'
log_statement = 'all'
logging_collector = on

Solution 6 - Postgresql

Set log_statement to all:

http://www.postgresql.org/docs/8.3/static/runtime-config-logging.html#GUC-LOG-STATEMENT">Error Reporting and Logging - log_statement

Solution 7 - Postgresql

+1 to above answers. I use following config

log_line_prefix = '%t %c %u ' # time sessionid user
log_statement = 'all'

Solution 8 - Postgresql

Just to have more details for CentOS 6.4 (Red Hat 4.4.7-3) running PostgreSQL 9.2, based on the instructions found on this web page:

Set (uncomment) log_statement = 'all' and log_min_error_statement = error in /var/lib/pgsql/9.2/data/postgresql.conf.
Reload the PostgreSQL configuration. For me, this was done by running /usr/pgsql-9.2/bin/pg_ctl reload -D /var/lib/pgsql/9.2/data/.
Find today's log in /var/lib/pgsql/9.2/data/pg_log/

Solution 9 - Postgresql

There is an extension in postgresql for this. It's name is "pg_stat_statements". https://www.postgresql.org/docs/9.4/pgstatstatements.html

Basically you have to change postgresql.conf file a little bit:

shared_preload_libraries= 'pg_stat_statements'
pg_stat_statements.track = 'all'

Then you have to log in DB and run this command:

create extension pg_stat_statements;

It will create new view with name "pg_stat_statements". In this view you can see all the executed queries.

Solution 10 - Postgresql

You should also set this parameter to log every statement:

log_min_duration_statement = 0

Solution 11 - Postgresql

I was trying to set the log_statement in some postgres config file but in fact the file was not read by our postgres.

I confirmed that using the request :

select *
from pg_settings

[...]
log_statement	none # That was not the value i was expected for !!!

I use this way https://stackoverflow.com/a/41912295/2294168

command: postgres -c config_file=/etc/postgresql.conf

Solution 12 - Postgresql

Dynamically we can enable/disable the logging in 2 ways

Change the global variables in DB and reload the configuration a) Set log_statement = 'all'; or set log_min_duration_statement = 0; b) select pg_reload_conf();
From the Linux command line, edit the postgres configuration file, change the log related parameters log_min_duration_statement = 0 log_statement = 'all' Reload the configuration file su - postgres /usr/bin/pg_ctl reload

In both these cases, we should not be doing a Postgres restart. We can dynamically enable/disable logging with configuration reload.

I hope this should be helpful.

Content Type	Original Author	Original Content on Stackoverflow
Question	Paul	View Question on Stackoverflow
Solution 1 - Postgresql	Jarret Hardie	View Answer on Stackoverflow
Solution 2 - Postgresql	vijay	View Answer on Stackoverflow
Solution 3 - Postgresql	A T	View Answer on Stackoverflow
Solution 4 - Postgresql	Rix Beck	View Answer on Stackoverflow
Solution 5 - Postgresql	Latif Premani	View Answer on Stackoverflow
Solution 6 - Postgresql	Chad Birch	View Answer on Stackoverflow
Solution 7 - Postgresql	Shekhar	View Answer on Stackoverflow
Solution 8 - Postgresql	Zoltán	View Answer on Stackoverflow
Solution 9 - Postgresql	Delirante	View Answer on Stackoverflow
Solution 10 - Postgresql	H.Ç.T	View Answer on Stackoverflow
Solution 11 - Postgresql	Ser	View Answer on Stackoverflow
Solution 12 - Postgresql	Suresh	View Answer on Stackoverflow