I want to delete this post
You should create index
CREATE INDEX join_reachEffect_user ON default('User|' || TOSTRING(`user`)) USING GSI
and change your query to
SELECT count(*) FROM reachEffect u LEFT OUTER JOIN reachEffect ca ON KEY ('User|' || TOSTRING(ca.`user`)) FOR u WHERE u._type = 'User' AND (ca._type = 'Campaign' OR ca._type IS missing)
is this you want?
I know I can do this I have done this but I need like above can I do it ??