StackOverflow2013

Note that there are some explanatory texts on larger screens.

plurals

PO
text
Body
copied!<p>One of the simplest ways to improve things is to just have fewer entities in the first place. I can't really think of a terribly good reason why pages, questions and answers need to be separate entities. I suspect you normally display all of the questions on a single page in the same request, without exception. If that's really the case, just keep them in one entity. </p> <p>It does make a lot of sense to use the Exam entities as the parent for pages; for one thing, each exam is probably limited to a reasonable, small number of pages, so scaling this up probably won't hurt much.</p> <p>On the other hand, there probably <em>are</em> a great many exams per subject, and for that reason, subjects should <em>not</em> appear in the ancestry of exams (and by extension, pages). </p> <p>If, for some reason you needed to delete all of the exams in the subject of math, even if they were in the same entity group, you'd probably be unable to complete the whole delete in one transaction without timing out. You might even have trouble completing the delete in a single request. </p> <p>That suggests that you should be using the Task Queue for this operation. When a cascading change on a subject occurs, the request handler needs to insert a new task and then just return successfully. don't forget to just update the subject entity right there in the request handler.</p> <p>The task queue pulls a block of affected entities from the datastore, updates them, and then checks the time. If there is still more time available for continued updates, it pulls another block of entities, and so on, until none remain. If time is almost up, the task just adds itself back to the queue so it can restart where it left off when it respawns.</p> <p>It's a good idea to schedule the first task at least a few seconds into the future of the initial request, so that if, for instance, the subject was deleted, the delete can propagate to future requests and no new exams in that subject can be created by the time the task starts.</p>

Querying!

Guidance

An individual column

Larger individual text columns get their own page to allow for proper reading.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload