Re: BUG #19538: ALTER SYSTEM adds extra quotes

PG Bug reporting form <noreply(at)postgresql(dot)org> writes:
> The following command adds extra quotes to postgresql.auto.conf:
> ALTER SYSTEM SET shared_preload_libraries = 'pg_stat_statements, auth_delay,
> auto_explain, pg_prewarm';
> The result entry in postgresql.auto.conf is:
> shared_preload_libraries = '"pg_stat_statements, auth_delay, auto_explain,
> pg_prewarm"'
> As a result, PostgreSQL tries to load the entire string as a single library
> name and reports the following error in /var/log/postgresql:
> FATAL: could not access file "pg_stat_statements, auth_delay, auto_explain,
> pg_prewarm": Nincs ilyen fájl vagy könyvtár

This behavior is correct; what's wrong is the SQL syntax you used.
You should have written

ALTER SYSTEM SET shared_preload_libraries = pg_stat_statements, auth_delay,
auto_explain, pg_prewarm;

since what you are providing is a list, not a single value that
happens to contain some commas. (It wouldn't matter in this case
whether you quote the individual values; though if any of them match
a SQL reserved word, it'd need quotes.)

I know this is confusing, because the rules are different when you
are writing a list directly in postgresql.conf. But, well, SQL is
not postgresql.conf.

regards, tom lane