Skip to main content
duckrun

PyPI Downloads Downloads/month Python License

Disclaimer: This is a personal project. It is not affiliated with, endorsed by, or supported by any employer or vendor. No warranty — use it at your own risk.

duckrun runs SQL in DuckDB and reads/writes Delta Lake via delta-rs — locally or on OneLake / S3 / GCS / ADLS. It's just glue: DuckDB executes · delta-rs materializes · Arrow bridges · dbt orchestrates. Two ways to use it:

  • connect() — a notebook helper to query and write Delta straight from SQL (this page);
  • a dbt adapter that materializes models as Delta tables.

Concurrent writers are first-class: every write is snapshot-pinned and fails loud rather than silently interleaving.

Install

In a Microsoft Fabric notebook, upgrade and restart the kernel (duckrun needs duckdb ≥ 1.5.4, which is newer than the bundled stable build; it fails loud at connect() otherwise):

!pip install duckrun --upgrade
notebookutils.session.restartPython()

Quickstart — OneLake in a notebook

import duckrun

# Read-only by default — explore a lakehouse safely, no chance of an accidental write.
# Use the workspace + lakehouse GUIDs (friendly names hit an upstream OneLake read bug for now).
conn = duckrun.connect("abfss://<workspace_id>@onelake.dfs.fabric.microsoft.com/<lakehouse_id>/Tables/dbo")

conn.sql("SHOW TABLES").show()
conn.sql("select status, count(*) from orders group by status").show()
df = conn.table("orders").toPandas()          # or .toArrow() for a streaming RecordBatchReader

# Time travel: list the versions, then read one
from duckrun import DeltaTable
DeltaTable.forName(conn, "orders").history()   # newest-first commits: version, timestamp, operation, …
conn.read.format("delta").option("versionAsOf", 0).load(".../Tables/dbo/orders").show()

Need to write? Opt in with read_only=False:

conn = duckrun.connect("abfss://…/Tables/dbo", read_only=False)

# write Delta straight from SQL
conn.sql("select * from orders where amount > 0") \
    .write.mode("overwrite").saveAsTable("clean_orders")

# raw DML routes to delta-rs (insert / update / delete / create table as / alter / drop)
conn.sql("delete from clean_orders where amount = 0")

# upsert — snapshot-pinned automatically, nothing extra to pass
from duckrun import DeltaTable
src = conn.sql("select * from updates")
DeltaTable.forName(conn, "clean_orders").merge(src, "target.id = source.id") \
    .whenMatchedUpdateAll().whenNotMatchedInsertAll().execute()

conn.stop()

Multiple catalogs — attach more lakehouses and read/join across them by three-part name. In Fabric a Warehouse is just a write-locked Lakehouse, so attach it read_only=True next to a writable one:

conn.attach("abfss://…/warehouse.Warehouse/Tables", name="warehouse", read_only=True)
conn.attach("/data/reference", name="local")
conn.sql("select * from warehouse.mart.facts f join local.dbo.lookup l on l.id = f.id").show()

Works the same against a local path, s3://, gs://, or az://. Full method map: Connection API · Spark/Delta coverage · live multi-catalog demo.

dbt adapter

duckrun is also a dbt adapter — a thin wrapper around dbt-duckdb that adds Delta-backed table / incremental materializations (everything else dbt-duckdb gives you is inherited). Point a profile at a lakehouse and dbt run:

# ~/.dbt/profiles.yml
my_project:
  outputs:
    dev:
      type: duckrun
      root_path: "abfss://<workspace_id>@onelake.dfs.fabric.microsoft.com/<lakehouse_id>/Tables"

Multiple lakehouses in one project — declare extra write roots as named catalogs: and send a model to one with the standard dbt +database: <alias> config (e.g. a Bronze/Silver/Gold medallion across three Fabric Lakehouses). ref() and joins resolve across them:

    dev:
      type: duckrun
      root_path: "abfss://ws@onelake.dfs.fabric.microsoft.com/LH_Silver.Lakehouse/Tables"  # default
      catalogs:
        lh_bronze: { root_path: "abfss://ws@onelake.dfs.fabric.microsoft.com/LH_Bronze.Lakehouse/Tables" }
        lh_gold:   { root_path: "abfss://ws@onelake.dfs.fabric.microsoft.com/LH_Gold.Lakehouse/Tables" }
-- models/bronze/raw_events.sql → lands in LH_Bronze
{{ config(materialized='incremental', database='lh_bronze', unique_key='id') }}
select ...

Profiles, materializations, incremental strategies (incl. append_if_unchanged), sources, and automatic compaction/vacuum are all in docs/dbt-adapter.md.

See it on real projects: aemo and coffee are runnable starters, and parity_tests/ runs real type: duckdb projects (jaffle_shop, sde, MRR, TechFlow, Tuva) unchanged on duckrun and diffs the output against dbt-duckdb.

Building with an AI assistant

duckrun ships a guide so AI coding assistants get the adapter's defaults right (several differ from other dbt adapters). For Claude Code:

/plugin marketplace add djouallah/duckrun
/plugin install duckrun-projects@duckrun

Other assistants read the AGENTS.md at the repo root, which points to the full guide. None of this is required to use duckrun.

How it works

Two engines, split cleanly: DuckDB runs every query and reads Delta through delta_scan views, delta-rs handles every write, an Arrow C-stream bridges them, and dbt orchestrates on top.

duckrun architecture: DuckDB executes SQL and reads Delta via delta_scan; an Arrow C-stream bridges to delta-rs, which handles every write and commits against the read version (OCC); dbt orchestrates on top

Writes are snapshot-pinned: the read is fixed at delta_scan(…, version => N) and the write commits against N, so a concurrent commit is rejected with CommitFailedError instead of silently overwriting a lost update.

Two writers race on one table: Writer A reads v5 and computes; Writer B commits v6 in between; A's commit against v5 is rejected with CommitFailedError instead of silently overwriting B

More on the design: Design document · Snapshot isolation.

Docs

Browse the rendered docs site at djouallah.github.io/duckrun — or read the markdown here:

Doc What's in it
Connection API The duckrun.connect() notebook API + the live per-method scorecard.
Spark / Delta coverage What the connect() surface maps to in PySpark / Delta.
dbt adapter Profiles, materializations, incremental strategies, sources, maintenance, limitations.
Design document Why delta-rs (not DuckDB's native Delta writer), why Delta (not Iceberg), why a separate adapter.
Snapshot isolation How a read-modify-write is fenced to the version you read, and how it compares to delta-rs/Spark/SQL Server.
dbt adapter conformance Official dbt-tests-adapter results, regenerated on every push to main.
Incremental MERGE benchmark ~60M-row TPCH merge / append / overwrite scorecard — the release gate.

License

MIT

Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

duckrun-0.3.30.tar.gz (123.8 kB view details)

Uploaded Source

Built Distribution

If you're not sure about the file name format, learn more about wheel file names.

duckrun-0.3.30-py3-none-any.whl (131.5 kB view details)

Uploaded Python 3

File details

Details for the file duckrun-0.3.30.tar.gz.

File metadata

  • Download URL: duckrun-0.3.30.tar.gz
  • Upload date:
  • Size: 123.8 kB
  • Tags: Source
  • Uploaded using Trusted Publishing? Yes
  • Uploaded via: twine/6.1.0 CPython/3.13.12

File hashes

Hashes for duckrun-0.3.30.tar.gz
Algorithm Hash digest
SHA256 f72ea144bb17736ef1f1301f4535fba4c78f1369115676650b514b7715160de9
MD5 7e48d266aeea857afeeb04cb504b6042
BLAKE2b-256 76eac5bf2c4ebf2c3343e2c6ab8925cbf5d42ac5dc978b6f6c3bb5d8141b280f

See more details on using hashes here.

Provenance

The following attestation bundles were made for duckrun-0.3.30.tar.gz:

Publisher: publish.yml on djouallah/duckrun

Attestations: Values shown here reflect the state when the release was signed and may no longer be current.

File details

Details for the file duckrun-0.3.30-py3-none-any.whl.

File metadata

  • Download URL: duckrun-0.3.30-py3-none-any.whl
  • Upload date:
  • Size: 131.5 kB
  • Tags: Python 3
  • Uploaded using Trusted Publishing? Yes
  • Uploaded via: twine/6.1.0 CPython/3.13.12

File hashes

Hashes for duckrun-0.3.30-py3-none-any.whl
Algorithm Hash digest
SHA256 b8b679480c74ca3b4dd80f0b544296f2158342d8567fe8fe214dccfe4b794a91
MD5 f43a7cd24dc279c311bb077424b98d32
BLAKE2b-256 58d3b417211836ec1ee0a656c2d3e489b49bce0f8ff2dbac72789bad3dce52b0

See more details on using hashes here.

Provenance

The following attestation bundles were made for duckrun-0.3.30-py3-none-any.whl:

Publisher: publish.yml on djouallah/duckrun

Attestations: Values shown here reflect the state when the release was signed and may no longer be current.

Release history Release notifications | RSS feed

Supported by

AWS Cloud computing and Security Sponsor Datadog Monitoring Depot Continuous Integration Fastly CDN Google Download Analytics Pingdom Monitoring Sentry Error logging StatusPage Status page