Incremental Compaction Strategy (ICS)

[marvin-j97]

Use target_size to chunk segments into runs of segments.

Comparing:

• Tiered: merges N segments into a bigger segment into the next level
• Levelled: keeps same-sized segments disjunct in each level, just increasing the segment cap per level
• Incremental: mix between both. Instead of creating one bigger segment, its split into same sized segments, which creates a sorted run. There may be N sorted runs per level, which can then be merged into the next level in a staggered fashion, solving the double size problem: