Heikki Linnakangas

> It is quadratic on ingesting this files: to append N+1'st delta we need first to extract aux directory, i.e. apply all previous N deltas. This is why it is...

Here's a screen capture of what the simulator output looks like https://github.com/neondatabase/neon/assets/191602/5b47d977-26b3-4f06-ab79-22ddd0b17035

> Thinking forward, pluggable compaction will play well with a couple of other places I'm thinking about adding "special" compactions in future: > > * Sharding splits, where we might...

> > Other thoughts from reading this: > > > > * The existence of the `Timeline::compact_tiered` method suggests that maybe the CopmactionJobExecutor trait should expose a little bit more...

I'd like to move this forward. For review, I think there are two criteria: 1. Is this safe to merge now? The new algorithm is added behind a new tenant...

Rebased this, fixing conflicts. The conflicts were mostly from PR #4938, but they weren't too hard to resolve.

I wonder if anyone else has seen this problem, or if it's just me?

The new compaction code in https://github.com/neondatabase/neon/pull/6830/ no longer calls `count_deltas`. (It needs testing to see if it introduces other problems of course)