pub fn pg_guc_boot_value(name: &str) -> Option<&'static str>Expand description
v7.39 (tz epic) — host-injected IANA timezone lookups (the no_std engine can’t read the system zoneinfo directory; spg-tzif is the std-side implementation). All instants are MICROSECONDS. UTC offset (µs east) of a zone at a UTC instant; None = unknown zone. v7.39 (round 534) — the compiled-in default PG18 reports for a configuration parameter, for the wire’s own SHOW shortcut.
The pgwire layer answers SHOW <name> from a small canned list
before the statement ever reaches the engine, so it needs the same
inventory the engine reads or the two disagree — which they did:
SHOW fsync over the wire returned an empty row.