skip files before lookup key in internal key ordering

db/version_set.cc

@@ -200,13 +200,6 @@ class FilePicker {
               break;
             }
           }
-          if (cmp_largest == 0 &&
-              GetInternalKeySeqno(f->largest_key) == kMaxSequenceNumber) {
-            assert(ExtractValueType(f->largest_key) == kTypeRangeDeletion);
-            // Key falls at the range tombstone sentinel endpoint. Proceed to
-            // next level.
-            break;
-          }
         }
 #ifndef NDEBUG
         // Sanity check to make sure that the files are correctly sorted
@@ -315,10 +308,23 @@ class FilePicker {
             search_right_bound_ =
                 static_cast<int32_t>(curr_file_level_->num_files) - 1;
           }
+          // `search_right_bound_` is an inclusive upper-bound, but since it was
+          // determined based on user key, it is still possible the lookup key
+          // falls to the right of `search_right_bound_`'s corresponding file.
+          // So, pass a limit one higher, which allows us to detect this case.
           start_index =
               FindFileInRange(*internal_comparator_, *curr_file_level_, ikey_,
                               static_cast<uint32_t>(search_left_bound_),
-                              static_cast<uint32_t>(search_right_bound_));
+                              static_cast<uint32_t>(search_right_bound_) + 1);
+          if (start_index == search_right_bound_ + 1) {
+            // `ikey_` comes after `search_right_bound_`. The lookup key does
+            // not exist on this level, so let's skip this level and do a full
+            // binary search on the next level.
+            search_left_bound_ = 0;
+            search_right_bound_ = FileIndexer::kLevelMaxIndex;
+            curr_level_++;
+            continue;
+          }
         } else {
           // search_left_bound > search_right_bound, key does not exist in
           // this level. Since no comparison is done in this level, it will