dbslice

Extract minimal, referentially-intact database subsets for local development and debugging.

The Problem

Copying an entire production database to your machine is infeasible. But reproducing a bug often requires having the exact data that caused it. dbslice solves this by extracting only the records you need, following foreign key relationships to ensure referential integrity.

dbslice — seed to subset

Quick Start

# Install globally
uv tool install dbslice   # or: pip install dbslice
Extract an order and all related records
dbslice extract postgres://localhost/myapp --seed "orders.id=12345" > subset.sql
Import into local database
psql -d localdb < subset.sql

Features

Zero-config start -- Introspects schema automatically, no data model file required
Single command -- Extract complete data subsets with one CLI invocation
Safe by default -- Auto-detects and anonymizes sensitive fields (emails, phones, SSNs, etc.)
Compliance profiles -- Built-in GDPR, HIPAA Safe Harbor, and PCI-DSS profiles with two-phase PII scanning
Column mapping UI -- Local browser UI to visually map columns, apply compliance profiles, and export config
Multiple output formats -- SQL, JSON, and CSV
Streaming -- Memory-efficient extraction for large datasets (100K+ rows)
Virtual foreign keys -- Support for Django GenericForeignKeys and implicit relationships via config
Config files -- YAML-based configuration for repeatable extractions
Validation -- Checks referential integrity of extracted data

Database Support

| Database | Status | |------------|-----------------------| | PostgreSQL | Fully supported | | MySQL | Planned (not yet implemented) | | SQLite | Planned (not yet implemented) |

Installation

# Install with uv (recommended)
uv add dbslice
Try without installing
uvx dbslice --help
Or with pip
pip install dbslice

Usage

Basic Extraction

# Extract by primary key
dbslice extract postgres://user:pass@host:5432/db --seed "orders.id=12345"
Extract with WHERE clause
dbslice extract postgres://localhost/db --seed "orders:status='failed' AND created_at > '2024-01-01'"
Multiple seeds
dbslice extract postgres://localhost/db \
  --seed "orders.id=100" \
  --seed "orders.id=101"

Control Traversal

# Limit depth (default: 3)
dbslice extract postgres://... --seed "orders.id=1" --depth 2
Direction: up (parents only), down (children only), both (default)
dbslice extract postgres://... --seed "orders.id=1" --direction up

Anonymization

# Auto-anonymize detected sensitive fields
dbslice extract postgres://... --seed "users.id=1" --anonymize
Redact additional fields
dbslice extract postgres://... --seed "users.id=1" --anonymize --redact "audit_logs.ip_address"

Column Mapping UI

Map columns visually, apply compliance profiles, and generate a ready-to-use config — all from a local browser UI.

dbslice map postgres://localhost/myapp
Custom port
dbslice map postgres://localhost/myapp --port 8888
Also works with uvx (no install needed)
uvx dbslice map postgres://localhost/myapp

Map columns to anonymization rules	Generate and export config

Runs on 127.0.0.1:9473 with a one-time session token — no data leaves your machine. Apply GDPR, HIPAA, or PCI-DSS profiles with one click, review what gets masked, then download the YAML.

Compliance Profiles

# HIPAA Safe Harbor — auto-masks all 18 identifier types
dbslice extract postgres://... --seed "patients.id=1" --compliance hipaa --compliance-strict
Multiple profiles + audit manifest
dbslice extract postgres://... --seed "users.id=1" --compliance gdpr --compliance pci-dss -f subset.sql
Produces subset.sql + subset.manifest.json

Output Formats

# SQL (default)
dbslice extract postgres://... --seed "orders.id=1" --output sql
JSON fixtures
dbslice extract postgres://... --seed "orders.id=1" --output json --out-file fixtures/
CSV
dbslice extract postgres://... --seed "orders.id=1" --output csv --out-file data/

Virtual Foreign Keys

For relationships not defined in the database schema (Django GenericForeignKeys, implicit relationships):

# dbslice.yaml
database:
  url: postgres://localhost:5432/myapp
virtual_foreign_keys:
  
source_table: notifications
    source_columns: [object_id]
    target_table: orders
    description: "Generic FK to orders via ContentType"
source_table: audit_log
    source_columns: [user_id]
    target_table: users
    description: "Implicit FK without DB constraint"

dbslice extract --config dbslice.yaml --seed "users.id=1"

Inspect Schema

dbslice inspect postgres://localhost/myapp

Configuration File

# Generate config from database
dbslice init postgres://localhost/myapp --out-file dbslice.yaml
Use config
dbslice extract --config dbslice.yaml --seed "orders.id=12345"

How It Works

Introspect -- Reads database schema to discover tables and foreign key relationships
Traverse -- Starting from seed record(s), follows FK relationships via BFS
Extract -- Fetches all identified records
Sort -- Topologically sorts tables for correct INSERT order
Output -- Generates SQL/JSON/CSV with proper escaping

Comparison

| Feature | dbslice | Jailer | Greenmask | slice-db | |---------|---------|--------|-----------|----------| | Language | Python | Java | Go | Ruby | | Configuration | Zero-config | Requires model file | Config required | Manual YAML | | Setup time | Seconds | Hours | Medium | Medium | | Anonymization | Built-in (Faker) | Plugin-based | Advanced transformers | Not available | | Compliance profiles | GDPR, HIPAA, PCI-DSS | None | None | None | | Column mapping UI | Built-in (local) | None | None | None | | PII value scanning | Two-phase (pre/post mask) | None | None | None | | Subsetting | FK traversal | FK traversal | Limited | FK traversal | | Output formats | SQL, JSON, CSV | SQL, XML, CSV | SQL | SQL only | | Cycle handling | Automatic | Manual config | N/A | Manual | | Streaming | Built-in | Configurable | Built-in | Not available | | Maintenance | Active | Active | Active | Unmaintained |

dbslice is the lightweight, zero-config Python option: install and extract in under a minute.

Development

git clone https://github.com/nabroleonx/dbslice.git
cd dbslice
uv sync --dev
uv run pytest

License

MIT

--- Tranlated By Open Ai Tx | Last indexed: 2026-07-19 ---