PostgreSQL 10 High Performance - Third Edition

Allowed change context

Every configuration setting has an associated context in which it's allowed to be changed.

The context is as follows:

pgbench=# select distinct context from pg_settings order by 1; 
 context       
------------------- 
 backend 
 internal 
 postmaster 
 sighup 
 superuser 
 superuser-backend 
 user 

The best way to determine the allowed change context for a setting is to ask the database directly. The following example shows one entry with each context type (the actual result if you run this query will include every server parameter):

postgres=# select name,context from pg_settings; name | context ----------------------------+------------ archive_command | sighup archive_mode | postmaster block_size | internal log_connections | backend log_min_duration_statement ...