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Streaming Iceberg Nexmark observations

2,000,000 deterministic events; parallelism 4; four-bucket input/output tables. All times include streaming completion and final drain/commit.

Query State / mini-batch Variant StreamFusion with stock Iceberg IO median [range], s StreamFusion median [range], s Median ratio
q0 disk-off exact 1.120 [1.095–1.184] 0.629 [0.603–0.633] 1.78×
q0 memory-off exact 1.185 [1.155–1.537] 0.657 [0.642–0.684] 1.80×
q3 disk-off exact 0.583 [0.571–0.609] 0.604 [0.567–0.674] 0.96×
q3 memory-off exact 0.499 [0.482–0.501] 0.446 [0.433–0.468] 1.12×
q4 disk-off exact 19.692 [9.537–29.457] 20.823 [16.762–28.009] 0.95×
q4 memory-off exact 9.572 [3.034–16.923] 12.097 [2.185–20.627] 0.79×
q9 disk-off exact 19.834 [13.563–36.062] 40.174 [24.850–45.826] 0.49×
q9 memory-off exact 37.880 [30.560–42.000] 4.667 [4.559–26.471] 8.12×

Exact-query aggregates

Geometric means use every exact-query cell in each mode; labelled expression variants remain separate above. Throughput is nominal corpus events divided by median end-to-end time, including startup, checkpoints and drain.

State / mini-batch Queries Geomean ratio StreamFusion with stock Iceberg IO corpus events/s, range StreamFusion corpus events/s, range
disk-off 4 0.95× 100,837–3,433,234 49,783–3,310,518
memory-off 4 1.90× 52,799–4,008,403 165,332–4,484,866

README query selection

Each query contributes once per mode, using its existing labelled variant when present. Median ratios retain all repetitions. The secondary headline sample uses the first memory sample or the best of the first two disk samples.

State / mini-batch Queries Geomean median ratio Geomean headline-sample ratio
disk-off 4 0.95× 0.86×
memory-off 4 1.90× 2.03×

Headline sampling convention

Memory uses the first measured sample; disk uses the best of the first two. The repeated medians and complete ranges above remain the primary results.

Query State / mini-batch Variant StreamFusion with stock Iceberg IO, s StreamFusion, s Ratio
q0 disk-off exact 1.120 0.629 1.78×
q0 memory-off exact 1.537 0.684 2.25×
q3 disk-off exact 0.571 0.567 1.01×
q3 memory-off exact 0.482 0.468 1.03×
q4 disk-off exact 9.537 16.762 0.57×
q4 memory-off exact 9.572 12.097 0.79×
q9 disk-off exact 13.563 24.850 0.55×
q9 memory-off exact 42.000 4.559 9.21×

Raw samples, warmups, parity checks, plans, committed table locations and native/fallback task/file witnesses are retained in this artifact directory. PROCTIME q12 validates per-bidder count conservation and includes waiting for the final processing-time window.

Per-cell timing, checkpoint and sampled-memory metrics retain separate phase medians. Phase medians need not sum to the total median. Memory peaks are sampled during progress polling, not exhaustive job maxima.