lsm-compaction-is-full-merge

Status: IN

`compact()` merges all SSTables into a single new SSTable (size-tiered, single-level), not incremental or leveled — simpler but with higher space amplification.

Source: entries/2026/05/28/log-structured-merge-tree-lsm.md

Example

def compact(self):
    entries = {}
    for sst in self._sstables:
        for key, value in sst.scan():
            entries[key] = value  # newer overwrites older
    # write single new SSTable from merged entries

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