old_contents: # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  #
  # http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  
  from pyramid.view import view_config
  from sqlalchemy.orm import joinedload
  
  from warehouse.cache.origin import origin_cache
  from warehouse.packaging.models import Project, Release
  from warehouse.xml import XML_CSP
  
  
  @view_config(
      route_name="rss.updates",
      renderer="rss/updates.xml",
      decorator=[
          origin_cache(
              1 * 24 * 60 * 60,                         # 1 day
              stale_while_revalidate=1 * 24 * 60 * 60,  # 1 day
              stale_if_error=5 * 24 * 60 * 60,          # 5 days
          ),
      ],
  )
  def rss_updates(request):
      request.response.content_type = "text/xml"
  
      request.find_service(name="csp").merge(XML_CSP)
  
      latest_releases = (
          request.db.query(Release)
                    .options(joinedload(Release.project))
                    .order_by(Release.created.desc())
                    .limit(40)
                    .all()
      )
  
      return {"latest_releases": latest_releases}
  
  
  @view_config(
      route_name="rss.packages",
      renderer="rss/packages.xml",
      decorator=[
          origin_cache(
              1 * 24 * 60 * 60,                         # 1 day
              stale_while_revalidate=1 * 24 * 60 * 60,  # 1 day
              stale_if_error=5 * 24 * 60 * 60,          # 5 days
          ),
      ],
  )
  def rss_packages(request):
      request.response.content_type = "text/xml"
  
      request.find_service(name="csp").merge(XML_CSP)
  
      newest_projects = (
          request.db.query(Project)
                    .options(joinedload(Project.releases))
                    .order_by(Project.created.desc())
                    .filter(Project.releases.any())
                    .limit(40)
                    .all()
      )
  
      return {"newest_projects": newest_projects}
  
new_contents: # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  #
  # http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  
  from pyramid.view import view_config
  from sqlalchemy.orm import joinedload, load_only
  
  from warehouse.cache.origin import origin_cache
  from warehouse.packaging.models import Project, Release
  from warehouse.xml import XML_CSP
  
  
  @view_config(
      route_name="rss.updates",
      renderer="rss/updates.xml",
      decorator=[
          origin_cache(
              1 * 24 * 60 * 60,                         # 1 day
              stale_while_revalidate=1 * 24 * 60 * 60,  # 1 day
              stale_if_error=5 * 24 * 60 * 60,          # 5 days
          ),
      ],
  )
  def rss_updates(request):
      request.response.content_type = "text/xml"
  
      request.find_service(name="csp").merge(XML_CSP)
  
      latest_releases = (
          request.db.query(Release)
                    .options(joinedload(Release.project))
                    .order_by(Release.created.desc())
                    .limit(40)
                    .all()
      )
  
      return {"latest_releases": latest_releases}
  
  
  @view_config(
      route_name="rss.packages",
      renderer="rss/packages.xml",
      decorator=[
          origin_cache(
              1 * 24 * 60 * 60,                         # 1 day
              stale_while_revalidate=1 * 24 * 60 * 60,  # 1 day
              stale_if_error=5 * 24 * 60 * 60,          # 5 days
          ),
      ],
  )
  def rss_packages(request):
      request.response.content_type = "text/xml"
  
      request.find_service(name="csp").merge(XML_CSP)
  
      newest_projects = (
          request.db.query(Project)
                    .options(load_only("created", "normalized_name"))
                    .options(joinedload(Project.releases, innerjoin=True)
                             .load_only("summary"))
                    .order_by(Project.created.desc())
                    .limit(40)
                    .all()
      )
  
      return {"newest_projects": newest_projects}
  
subject: Use an innerjoin to optimize the RSS view