post_version.post.versions.first.id caused an extra query for each post version:
SELECT "post_versions".* FROM "post_versions" WHERE "post_versions"."post_id" = $1 ORDER BY updated_at ASC, id asc LIMIT 1
post_version.post.versions.first.id caused an extra query for each post version:
SELECT "post_versions".* FROM "post_versions" WHERE "post_versions"."post_id" = $1 ORDER BY updated_at ASC, id asc LIMIT 1