• Conceptual Basis
• Overview And the Basic Idea
• Limitations
• Double Size Issue
• DB (Column Family) Size if num_levels=1
• Data Layout and Placement
• Sorted Runs
• Placement of Compaction Outputs
• Special case options.num_levels=1
• Compaction Picking Algorithm
• Precondition: n >= options.level0_file_num_compaction_trigger
• 1. Compaction triggered by age of data
• 2. Compaction Triggered by Space Amplification
• 3. Compaction Triggered by number of sorted runs while respecting size_ratio
• 4. Compaction Triggered by number of sorted runs without respecting size_ratio
• Subcompaction
• Options to Tune
• Estimate Write Amplification