# Duckdb

> DuckDB analytical database for OLAP workloads. Use for embedded analytics.

- Skill: `g1joshi/duckdb` (Agent Skill)
- Install (CLI): `npx skillmds@latest add g1joshi/duckdb`
- Raw SKILL.md: https://api.skillmd.com/api/skills/g1joshi/duckdb/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Data & Analytics
- Author: G1Joshi (https://skillmd.com/u/g1joshi)
- Updated: 2026-09-10
- Page: https://skillmd.com/skills/g1joshi/duckdb

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# DuckDB

DuckDB is "SQLite for Analytics". It is an in-process SQL OLAP database. It runs inside your application process and is blazing fast for analytical queries on local files (Parquet, CSV, JSON).

## When to Use

- **Local Analytics**: Analyze millions of rows on your laptop in seconds.
- **Data Engineering**: Process data in Python/R pipelines (replacement for Pandas).
- **Serverless Data Lake**: Query S3 parquet files directly via Lambda without a running warehouse.

## Quick Start (Python)

```python
import duckdb

# Query local CSV directly
duckdb.sql("SELECT avg(price) FROM 'sales.csv' WHERE region='US'").show()

# Connect to S3
duckdb.sql("INSTALL httpfs; LOAD httpfs;")
duckdb.sql("SELECT count(*) FROM 's3://my-bucket/data.parquet'")
```

## Core Concepts

### Vectorized Execution

Standard DBs process row-by-row. DuckDB processes batches of columns (Vectors), utilizing modern CPU SIMD instructions.

### Universal Format Reader

Can query CSV, JSON, Parquet, Arrow, SQLite, and Postgres tables as if they were local tables.

### Zero Dependencies

Single binary/library.

## Best Practices (2025)

**Do**:

- **Use Parquet**: It is the native language of analytics. DuckDB + Parquet is incredible.
- **Replace Pandas**: For datasets larger than RAM, DuckDB works (Disk spilling) where Pandas crashes.
- **Use explicitly typed SQL**: DuckDB’s SQL dialect is very friendly and standard (Postgres-compatible).

**Don't**:

- **Don't use for Multi-User OLTP**: It handles concurrency poorly (single writer). Use Postgres for that. Use DuckDB for analysis.

## References

- [DuckDB Documentation](https://duckdb.org/docs/)