Allowed change context

Every configuration setting has an associated context in which it's allowed to be changed. 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             | sihup
archive_mode                | postmaster
block_size                  | internal
log_connections             | backend
log_min_duration_statement  | superuser
search_path                 | user

The context field isn't documented very well in the official manual. Here are the meanings of the various settings you'll find there, sorted from hardest to easiest to change:

• internal: These settings are mainly database internals set at compile time. They're...