Conformance Test Suite
Round-trip verified against Apache Spark
Every scenario runs twice. DeltaForge writes and Spark reads; Spark writes and DeltaForge reads. Expected values are derived outside the engine under test, so a passing row means the round-trip matched bit-for-bit.
Delta Lake
4,263
Scenarios
4,263
125 skipped (writer-side gap)
Verified pass
4,138/ 4,138
100% of rated suite
Failures
0
Zero open issues
Pending verdicts
0
All rated scenarios decided
Apache Iceberg
3,784
Scenarios
3,784
1 skipped (writer-side gap)
Verified pass
2,889/ 3,783
76.4% of rated suite
Failures
0
Zero open issues
Pending verdicts
894
Inventory committed; verdict in flight
DeltaForge writes, Spark reads
df_writes.json
Spark writes, DeltaForge reads
spark_writes.json
All scenarios verified May 15, 2026. Both formats reflect this run.
Data refreshed each release from the round-trip generator.