How can I dynamically determine the current Postgres log file?

Question

Is there a standard way to figure out which is the most recent log file of the running Postgres instance?

pg_config, unfortunately, does not even give information about the log directory.

Answer 1

The logs are in the data directory, in directory pg_log. You can ask the database to get this information for you:

SELECT  
    pg_ls_dir AS filename,
    pg_size_pretty((pg_stat_file('pg_log/' || pg_ls_dir)).size),
    (pg_stat_file('pg_log/' || pg_ls_dir)).access,
    (pg_stat_file('pg_log/' || pg_ls_dir)).modification,
    (pg_stat_file('pg_log/' || pg_ls_dir)).creation -- Windows only
FROM
    pg_ls_dir('pg_log')
WHERE
    (pg_stat_file('pg_log/' || pg_ls_dir)).isdir = false
ORDER BY
    modification DESC
LIMIT 1;

If you want to read the content of a logfile, you can use pg_read_file().

You have to be superuser to get the information.