alter table users
  add column if not exists avatar_image_url text,
  add column if not exists profile_headline text not null default '',
  add column if not exists profile_bio text not null default '',
  add column if not exists website_url text,
  add column if not exists linkedin_url text,
  add column if not exists instagram_url text,
  add column if not exists youtube_url text,
  add column if not exists profile_is_public boolean not null default true;

create index if not exists users_public_instructor_profiles_index
  on users (id)
  where profile_is_public and role in ('instructor', 'admin');