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🦆 DuckDB Knowledge Base

DuckDB Study Flashcards

In-process analytical database engine built for lightning-fast vectorized SQL queries over local files. Click any card to flip and test your knowledge.

Card 1 of 10 Overview

What is DuckDB?

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Answer DuckDB

An embedded columnar analytical database engine (often called the SQLite for Analytics).

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Card 2 of 10 Engine

What is vectorized execution in DuckDB?

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Answer DuckDB

Queries process vectors of data values in CPU cache lines using SIMD instructions for maximum throughput.

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Card 3 of 10 File Access

Can DuckDB read Parquet files directly?

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Answer DuckDB

Yes, DuckDB can execute SQL queries directly against local or remote Parquet and CSV files without importing them into tables.

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Card 4 of 10 Ecosystem

How does DuckDB integrate with Python Pandas/Polars?

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Answer DuckDB

DuckDB can query Pandas DataFrames, Polars DataFrames, and Arrow tables directly zero-copy.

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Card 5 of 10 SQL Extensions

Does DuckDB support the QUALIFY clause?

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Answer DuckDB

Yes, DuckDB supports Snowflake-style QUALIFY clauses to filter window function outputs directly.

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Card 6 of 10 Concurrency

Is DuckDB single-threaded or multi-threaded?

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Answer DuckDB

DuckDB automatically parallelizes query execution across all available CPU cores.

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Card 7 of 10 Cloud Access

What is read_parquet('s3://...')?

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Answer DuckDB

A function allowing direct HTTP/S3 querying of remote Parquet data lakes.

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Card 8 of 10 Memory Management

How does DuckDB handle memory limits?

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Answer DuckDB

DuckDB gracefully spills intermediate data to disk when query memory usage exceeds RAM limits.

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Card 9 of 10 Export

What is COPY TO in DuckDB?

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Answer DuckDB

Exports query results directly into Parquet, CSV, or JSON files on disk.

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Card 10 of 10 Transactions

Does DuckDB support ACID transactions?

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Answer DuckDB

Yes, DuckDB features full ACID transactional semantics using Multi-Version Concurrency Control (MVCC).

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Need practical SQL queries for DuckDB?

Explore our ready-to-use copy-paste query recipes in the Cookbook.

View DuckDB Cookbook →