diagram
Init(2 /* dbs */, 49 /* batches */, 63 /* iters */, 45 /* snapshots */, 0 /* externalObjs */)
db2.RangeKeySet("c", "h", "@6", "foo")
snap9 = db2.NewSnapshot("a", "z")
db2.RangeKeyDelete("d", "f")
db2.Compact("g", "i", true /* parallelize */)
db2.Replicate(db1, "b", "f")
iter25 = db1.NewIter("", "", 2 /* key types */, "", "", false /* use L6 filters */, "@7" /* masking suffix */)
iter25.SeekGE("e", "")
----
                                                        Init(2 /* dbs */, 49 /* batches */, 63 /* iters */, 45 /* snapshots */, 0 /* externalObjs */)
            |-----------------------------|             db2.RangeKeySet("c", "h", "@6", "foo")
|-----------------------------------------------------| snap9 = db2.NewSnapshot("a", "z")
                  |-----------|                         db2.RangeKeyDelete("d", "f")
                                    |-----------|       db2.Compact("g", "i", true /* parallelize */)
      |-----------------------|                         db2.Replicate(db1, "b", "f")
                                                        iter25 = db1.NewIter("", "", 2 /* key types */, "", "", false /* use L6 filters */, "@7" /* masking suffix */)
                        |                               iter25.SeekGE("e", "")
|-----|-----|-----|-----|-----|-----|-----|-----|-----|
a     b     c     d     e     f     g     h     i     z

diagram
db2.RangeKeySet("apple", "raspberry", "", "")
snap9 = db2.NewSnapshot("banana", "durian", "guanabana", "pineapple")
db2.Compact("cranberry", "pear", true /* parallelize */)
----
|-------------------------------------------------------------| db2.RangeKeySet("apple", "raspberry", "", "")
       |------------------|       |----------------|            snap9 = db2.NewSnapshot("banana", "durian", "guanabana", "pineapple")
               |-----------------------------|                  db2.Compact("cranberry", "pear", true /* parallelize */)
|------|-------|----------|-------|----------|-----|----------|
apple  banana  cranberry  durian  guanabana  pear  pineapple  raspberry
