# Phase 2 gate — mongo-lite vs MongoDB 8.3.7, 1g dataset / ~16k docs
# Ratio < 1.0 = mongo-lite faster. Reproduce: bash tests/e2e/compare-run.sh 1g 16k
# This run includes roadmap item 1 (B+tree over the encoded keys).
# Compare: tests/e2e/results/phase1.txt (pre-tree baseline).

benchmark                                   mongo-lite              mongodb                 ratio
insertOne (sequential) ×200                 0.19 ms                 4.1 ms                  0.0x
bulk insert throughput                      810.4 MB/s              714.4 MB/s              1.1x
docs loaded                                 65,536                  65,536                  1.0x
createIndex({k: 1})                         50.8 ms                 82.4 ms                 0.6x
countDocuments({})                          1.5 ms                  13.8 ms                 0.1x
findOne({_id: <ObjectId>})                  0.57 ms                 0.67 ms                 0.9x
findOne({k: 500}) (indexed)                 0.57 ms                 1.8 ms                  0.3x
find({p: {$gte,$lt}}).count() (scan)        20.3 ms                 12.9 ms                 1.6x
find({}).sort({_id:-1}).limit(20)           6.2 ms                  2.7 ms                  2.3x
find({}, {proj}).limit(1000)                3.7 ms                  4.5 ms                  0.8x
aggregate $group by k                       11.5 ms                 15.5 ms                 0.7x
updateOne({_id}) ×50                        0.17 ms                 0.19 ms                 0.9x
updateMany({k: 7}, {$inc})                  1.8 ms                  6.7 ms                  0.3x
deleteOne({_id}) + insertOne                0.50 ms                 5.0 ms                  0.1x
node client RSS                             152 MB                  156 MB                  1.0x
server RSS                                  1974 MB                 1474 MB
kill -9 reopen                              0.8s                    1.3s
db on disk                                  1028MB                  96MB

# Item 1 (B+tree over encoded keys) deltas vs phase1:
#   updateMany   17.3 -> 1.8 ms   (2.8x slower than mongod -> 3.7x faster):
#                 entry removal was a per-entry binary search into a sorted
#                 array with an orderedRemove memmove behind it; now it is a
#                 descent plus a leaf-local slot removal.
#   createIndex  62.4 -> 50.8 ms  (bulk packing replaces append+sort)
#   findOne(k:500) indexed 0.64 -> 0.57 ms (unchanged shape, tree search)
#
# Remaining gaps and where they are addressed:
#   db on disk   11x  -> Phase 3 (block-compressed log)
#   sort+limit  2.3x  -> Phase 2 (ordered _id index)
#   range-scan  1.6x  -> Phase 4 (contiguous byte storage, not the matcher)
#   server RSS  1.3x  -> Phase 4 (per-document arena -> byte storage)