comment + fix mvcc version

Signed-off-by: Alex Chi <[email protected]>

Author: skyzh

mini-lsm-mvcc/src/compact/tiered.rs

@@ -90,7 +90,8 @@ impl TieredCompactionController {
                         .take(id + 1)
                         .cloned()
                         .collect::<Vec<_>>(),
-                    bottom_tier_included: id + 1 >= snapshot.levels.len(),
+                    // Size ratio trigger will never include the bottom level
+                    bottom_tier_included: false,
                 });
             }
         }

mini-lsm/src/compact/tiered.rs

@@ -90,6 +90,7 @@ impl TieredCompactionController {
                         .take(id + 1)
                         .cloned()
                         .collect::<Vec<_>>(),
+                    // Size ratio trigger will never include the bottom level
                     bottom_tier_included: false,
                 });
             }