dvt-core 0.1.55

DVT — cross-engine data transformation tool with DuckDB federation.

DVT — Data Virtualization Tool

Connect every database. Transform across engines. Materialize anywhere.

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DVT is a cross-engine data transformation tool built on dbt-core. Write SQL models that reference sources on any database, and DVT automatically handles cross-engine data movement and materializes results to any target.

No custom connectors. No complex config. Just SQL.

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How It Works

DVT extends dbt with federated query execution. When your sources and target live on the same engine, DVT pushes SQL directly to the database (identical to dbt). When they're on different engines, DVT transparently extracts, joins, and loads across engines:

flowchart LR
    subgraph Sources
        PG[(PostgreSQL)]
        MY[(MySQL)]
        SF[(Snowflake)]
        OR[(Oracle)]
    end

    subgraph DVT["DVT Engine"]
        direction TB
        SLING1[/"Sling Extract"/]
        DUCK[("DuckDB Cache<br/>.dvt/cache.duckdb")]
        SQL["Model SQL<br/>(joins, transforms)"]
        SLING2[/"Sling Load"/]
        SLING1 --> DUCK --> SQL --> SLING2
    end

    subgraph Targets
        TGT1[(Snowflake)]
        TGT2[(Databricks)]
        TGT3[(PostgreSQL)]
    end

    PG --> SLING1
    MY --> SLING1
    SF --> SLING1
    OR --> SLING1

    SLING2 --> TGT1
    SLING2 --> TGT2
    SLING2 --> TGT3

    style DVT fill:#f0f4ff,stroke:#336791,stroke-width:2px
    style DUCK fill:#FFF000,stroke:#333,color:#333
    style SLING1 fill:#0094b3,stroke:#333,color:#fff
    style SLING2 fill:#0094b3,stroke:#333,color:#fff
    style SQL fill:#29B5E8,stroke:#333,color:#fff

Two Execution Paths

Path	When	How
Pushdown	Source and target on same engine	SQL runs directly on the database via adapter — identical to dbt
Extraction	Sources on different engines	Sling extracts → DuckDB joins → Sling loads to target

The user never thinks about this — DVT decides the path automatically.

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Supported Engines

13 engines in one package (dvt-adapters):

	Engine	Type		Engine	Type
🐘	PostgreSQL	OLTP	❄️	Snowflake	Cloud DW
🐬	MySQL	OLTP	🧱	Databricks	Cloud DW
🦭	MariaDB	OLTP	🔷	BigQuery	Cloud DW
🟥	SQL Server	OLTP	🟧	Redshift	Cloud DW
🔴	Oracle	OLTP	🦆	DuckDB	Embedded
⚡	Spark	Distributed	🔵	Fabric	Cloud DW
	MySQL 5	Legacy

Any source → Any target. DVT handles the data movement.

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Installation

pip install dvt-core

Or with uv (recommended):

uv add dvt-core

This installs everything — dvt-core automatically pulls in dvt-adapters (all 13 engines), Sling, DuckDB, and all core dependencies.

Then bootstrap your environment:

dvt sync    # Installs database drivers, DuckDB extensions, Sling binary, cloud SDKs

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Quick Start

dvt init my_project && cd my_project   # Scaffold project
dvt sync                                # Install everything
dvt debug                               # Test all connections
dvt seed                                # Load CSV seed data
dvt run                                 # Run all models
dvt docs generate && dvt docs serve     # Engine-colored lineage docs

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Configuration

Connections (~/.dvt/profiles.yml)

my_project:
  target: pg_dev
  outputs:
    pg_dev:
      type: postgres
      host: localhost
      port: 5432
      user: analyst
      password: secret
      dbname: warehouse
      schema: public

    sf_prod:
      type: snowflake
      account: my-account
      user: loader
      password: secret
      database: ANALYTICS
      schema: PUBLIC
      warehouse: COMPUTE_WH

    mysql_crm:
      type: mysql
      host: mysql.example.com
      port: 3306
      user: reader
      password: secret
      database: crm

Sources (models/sources.yml)

The connection: field maps sources to their engine:

sources:
  - name: app_db           # On default target (no connection: needed)
    schema: public
    tables:
      - name: users
      - name: orders

  - name: crm              # On MySQL
    connection: mysql_crm
    schema: crm
    tables:
      - name: customers

  - name: marketing        # On Snowflake
    connection: sf_prod
    schema: PUBLIC
    tables:
      - name: campaigns

Cross-Engine Model

-- models/dim_customer_campaigns.sql
{{ config(materialized='table', target='sf_prod') }}

SELECT
    u.user_id,
    u.email,
    c.customer_name,
    m.campaign_name
FROM {{ source('app_db', 'users') }} u           -- Postgres
LEFT JOIN {{ source('crm', 'customers') }} c      -- MySQL
    ON u.email = c.email
LEFT JOIN {{ source('marketing', 'campaigns') }} m -- Snowflake
    ON u.user_id = m.user_id

DVT detects the 3 engines, extracts to DuckDB, executes the join, loads to Snowflake. You see standard dbt output.

Incremental Models

{{ config(materialized='incremental', incremental_strategy='append', target='sf_prod') }}

SELECT * FROM {{ source('app_db', 'orders') }}
{% if is_incremental() %}
WHERE order_date > (SELECT MAX(order_date) FROM {{ this }})
{% endif %}

DVT reads the watermark from the target, extracts only new rows, appends them.

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Two Dialects, One Project

Path	You Write	Runs On
Pushdown	Target's native SQL (Snowflake SQL, T-SQL, etc.)	Target database
Extraction	DuckDB SQL (Postgres-like)	Local DuckDB cache

Both coexist naturally. The dialect is determined by the execution path, not config.

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Commands

Core

Command	Description
dvt run	Execute models against targets
dvt run --full-refresh	Rebuild everything from scratch
dvt run --select +model_name	Run model and all ancestors
dvt build	Seeds + models + snapshots + tests in DAG order
dvt seed	Load CSVs via Sling (10-100x faster than dbt)
dvt test	Run data tests
dvt compile	Compile SQL without executing

DVT-Specific

Command	Description
dvt sync	Self-healing env bootstrap (drivers, DuckDB, Sling, cloud SDKs)
dvt debug	Test all connections with clean status output
dvt show --select model	Query locally via DuckDB (no target needed)
dvt retract	Drop models from targets in reverse DAG order
dvt retract --select +model	Drop a model and its entire upstream chain
dvt clean	Remove build artifacts + DuckDB cache

Documentation

Command	Description
dvt docs generate	Cross-engine catalog with engine-colored lineage
dvt docs serve	Serve documentation website

The docs UI features:

• Engine-colored nodes (each database has its brand color)
• Connection badges on every source and model
• Native column types from each engine
• Target and engine info in detail panels

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DuckDB Cache

DVT maintains a persistent cache at .dvt/cache.duckdb:

• Source tables: {source}__{table} — shared across models, reused between runs
• Model results: __model__{name} — for incremental {{ this }} references
• dvt run --full-refresh rebuilds the cache
• dvt clean deletes .dvt/ entirely

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--target Philosophy

--target switches environments, not engines:

dvt run --target dev_snowflake     # Dev Snowflake
dvt run --target prod_snowflake    # Prod Snowflake  ← Same engine, different env

Pushdown models use the target's SQL dialect. Extraction models use DuckDB SQL and are unaffected by target changes.

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dbt Compatibility

All dbt projects are valid DVT projects. When using a single adapter with no cross-engine references, DVT behaves identically to dbt.

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Community

• Discord: Join the DVT community
• Issues: Report a bug

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Links

PyPI	dvt-core · dvt-adapters
GitHub	dvt-core · dvt-adapters

Built On

DVT stands on the shoulders of three exceptional open-source projects:

Project	Role in DVT	License
dbt-core	DAG orchestration, SQL models, Jinja, testing, docs, adapters	Apache 2.0
Sling	High-performance data movement across 30+ connectors (free tier)	Apache 2.0
DuckDB	Local analytics engine — extraction compute, caching, dvt show	MIT

We are grateful to dbt Labs, Sling Data, and the DuckDB Foundation for building and open-sourcing these tools.

License

DVT is licensed under the Apache License 2.0.

Copyright 2025-2026 Hesham Badawi.
Licensed under the Apache License, Version 2.0.

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_{Built by Hesham Badawi — data engineer, for data engineers.}