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    <p>I have been in a similar situation. Instead of ReferenceProperty, I had parent/child relationships but the basics are the same. My current solution is not polished but at least it is efficient enough for reports and things with 200-1,000 entities, each with several subsequent child entities that require fetching.</p> <p>You can manually search for data in batches and set it if you want.</p> <pre><code># Given the posts, fetches all the data the template will need # with just 2 key-only loads from the datastore. posts = get_the_posts() author_keys = [Post.author.get_value_for_datastore(x) for x in posts] authors = db.get(author_keys) city_keys = [Author.city.get_value_for_datastore(x) for x in authors] cities = db.get(city_keys) for post, author, city in zip(posts, authors, cities): post.author = author author.city = city </code></pre> <p>Now when you render the template, no additional queries or fetches will be done. It's rough around the edges but I could not live without this pattern I just described.</p> <p>Also you might consider validating that none of your entities are <code>None</code> because db.get() will return None if the key is bad. That is getting into just basic data validation though. Similarly, you need to retry db.get() if there is a timeout, etc.</p> <p>(Finally, I don't think memcache will work as a primary solution. Maybe as a secondary layer to speed up datastore calls, but you need to work well if memcache is empty. Also, Memcache has several quotas itself such as memcache calls and total data transferred. Overusing memcache is a great way to kill your app dead.)</p>
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    1. POSpeeding up templates in GAE-Py by aggregating RPC calls
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    1. POSpeeding up templates in GAE-Py by aggregating RPC calls
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    1. COThe second code block is very helpful... I didn't think of zip and using it that way.. but the first block is actually a built in feature of the sdk... references are already cached after they're resolved once, so there's absolutely no need for that code..
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      1. USSudhir Jonathan
    2. COYou are correct. My code was copied from a similar situation not using ReferenceProperty. It would be nice to populate the property via some back-door rather than just blowing away the `.city` attribute. But I believe that would work in a pinch.
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    3. COHmm.. I am reading the code in google/appengine/ext/db/__init__.py in the SDK. It looks like a simple assignment works fine because it will call the ReferenceProperty's __set__() method. I will update the answer to be shorter and clearer.
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