How to do views random sort for all the items in a pager?

After struggling with this, it seems that when you use a pager, random sort can return the same item on multiple pages. In other words, Views random sort will randomly generate a list of results on each page, and you can get repeat results among different pages.

So what do you do if you want a random sort of all view results (on all pages of the pager) with no repeats?

You have to do it yourself.

Here's what I did.

First, add an integer field, Random Int.

Then, in hook_node_presave(), set the field to a random value.

function MYMODULE_node_presave(NodeInterface $node) {
  // Randomize the order in which missed cards appear.
  $node->set('field_int_random', MYMODULE_randomize_repeat_sort());
}

/**
 * Returns a number between 1 and 1000 for randomizing sort.
 *
 * @return int
 *   A random number from 1 to 1000.
 */
function MYMODULE_randomize_repeat_sort() {
  return mt_rand(1, 1000);
}

Finally, in your view, sort by the Random Int field instead of Views random sort.

Of course, the method here only randomizes the nodes on node save. For my use case, that is sufficient, but if you want a random sort per user, etc., you will need to do it a different way.

In your view under filter criteria, use Aggregation settings -> group results together.

This should remove your duplicate results