feldera · swanandx · Mar 15, 2026 · Mar 25, 2026
diff --git a/crates/adapters/Cargo.toml b/crates/adapters/Cargo.toml
@@ -246,3 +246,7 @@ required-features = ["with-avro"]
 name = "postgres_output"
 harness = false
 required-features = ["bench-mode"]
+
+[[bench]]
+name = "delta_encoder"
+harness = false
diff --git a/crates/adapters/benches/delta_encoder.rs b/crates/adapters/benches/delta_encoder.rs
@@ -0,0 +1,78 @@
+mod bench_common;
+
+use bench_common::{BenchKeyStruct, BenchTestStruct, build_indexed_batch, generate_test_data};
+use criterion::{BenchmarkId, Criterion, criterion_group, criterion_main};
+use dbsp_adapters::Encoder;
+use dbsp_adapters::integrated::delta_table::DeltaTableWriter;
+use feldera_types::transport::delta_table::{DeltaTableWriteMode, DeltaTableWriterConfig};
+use std::sync::Weak;
+use tempfile::TempDir;
+
+// ---------------------------------------------------------------------------
+// Delta-specific helpers
+// ---------------------------------------------------------------------------
+
+fn create_indexed_writer(threads: usize, table_uri: &str) -> DeltaTableWriter {
+    let config = DeltaTableWriterConfig {
+        uri: table_uri.to_string(),
+        mode: DeltaTableWriteMode::Truncate,
+        max_retries: Some(0),
+        threads: Some(threads),
+        object_store_config: Default::default(),
+    };
+    let key_schema = Some(BenchKeyStruct::relation_schema());
+    let mut value_schema = BenchTestStruct::relation_schema();
+    value_schema.materialized = true;
+    DeltaTableWriter::new(
+        Default::default(),
+        "bench_endpoint",
+        &config,
+        &key_schema,
+        &value_schema,
+        Weak::new(),
+    )
+    .unwrap()
+}
+
+// ---------------------------------------------------------------------------
+// Benchmarks
+// ---------------------------------------------------------------------------
+
+/// Benchmark parallel Delta table encoding with 100k records across 1/2/4/8 workers.
+fn bench_indexed_encode(c: &mut Criterion) {
+    let num_records = 100_000;
+    let data = generate_test_data(num_records);
+    let batch = build_indexed_batch(&data);
+
+    let mut group = c.benchmark_group("delta_indexed_encode");
+    group.throughput(criterion::Throughput::Elements(num_records as u64));
+
+    for workers in [1, 2, 4, 8] {
+        group.bench_with_input(
+            BenchmarkId::new("workers", workers),
+            &workers,
+            |b, &workers| {
+                // Each iteration needs a fresh directory since the writer
+                // creates real Parquet files.
+                b.iter_with_setup(
+                    || {
+                        let table_dir = TempDir::new().unwrap();
+                        let table_uri = table_dir.path().display().to_string();
+                        let writer = create_indexed_writer(workers, &table_uri);
+                        (writer, table_dir)
+                    },
+                    |(mut writer, _table_dir)| {
+                        writer.consumer().batch_start(0);
+                        writer.encode(batch.clone().arc_as_batch_reader()).unwrap();
+                        writer.consumer().batch_end();
+                    },
+                );
+            },
+        );
+    }
+
+    group.finish();
+}
+
+criterion_group!(benches, bench_indexed_encode);
+criterion_main!(benches);
diff --git a/crates/adapters/src/integrated.rs b/crates/adapters/src/integrated.rs
@@ -6,7 +6,7 @@ use feldera_types::program_schema::Relation;
 use std::sync::Weak;
 
 #[cfg(feature = "with-deltalake")]
-mod delta_table;
+pub mod delta_table;
 mod postgres;
 
 use crate::integrated::postgres::PostgresInputEndpoint;