[antirez]

We are going to have an option to XADD to insert elements in the middle. I commented more extensively about it in another reply, so inserting out of order later will be possible. However note that the pattern still works when you use a time as a field, you don't need range queries, but just want single-item identifiers. However the XADD option to insert out of order is really a thing that will hit Redis ASAP.

[nicpottier]

Excellent to hear this.

We use sorted sets as queues heavily and this would be a necessary thing for us to consider giving streams a go which would indeed be interesting from a memory savings (we sometimes have millions of items in our queues for a short time). Sometimes, say on error conditions, you want to stuff something back at the start of the queue (because the order of processing matters) instead of at the end as one example.. priority being another.