What's the best way to use a gist index on tsrange to check if a time occurs after the range?

# table (simplified) Table "public.events" Column | Type | Modifiers ------------------+-----------------------------+-------------------------------------------------------- id | integer | not null default nextval('events_id_seq'::regclass) duration | integer | not null start_at | timestamp without time zone | Indexes: "events_pkey" PRIMARY KEY, btree (id) "my_idx" gist (tsrange(start_at, end_at(events.*), '[)'::text)) # function CREATE FUNCTION end_at(rec events) RETURNS timestamp without time zone IMMUTABLE LANGUAGE SQL AS $$ SELECT $1.start_at + ($1.duration * ('00:00:01'::interval)); $$; # what I am already doing successfully The index is used for queries like this: -- check if current time is within the start and end times -- of event where localtimestamp > tsrange(start_at, events.end_at, '[)'). I'm pretty sure this is the semantics I want, and explain analyze` says it's using the index, but it's a bit ugly and I'm wondering if there's a better way to express this (and also am vaguely uncertain it's the semantics I want, as I am new to ranges). * where localtimestamp > upper(tsrange(start_at, events.end_at, '[)')) + a btree index on upper(tsrange(start_at, events.end_at, '[)')). This will work well, but requires keeping another index around. * where localtimestamp > events.end_at. + a btree index on events.end_at. Same situation as above. Is there a more elegant (or correct) way to achieve the first bullet point above? Any other ideas for how to go about this?