Open-Source Databases · TPC-Council

HammerDB

HammerDB is an open-source benchmarking tool for measuring database performance across major platforms including Oracle, SQL Server, Db2, PostgreSQL, MySQL, and MariaDB. It implements industry-standard TPC benchmarks (TPC-C for OLTP, TPC-H for OLAP) to help teams evaluate database workload capacity and scalability.

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Source: GitHub — github.com/TPC-Council/HammerDB

769

GitHub stars

150

Forks

Tcl

Primary language

GPL-3.0

License (OSI-approved)

Key facts

Objective fields from the source. Values we can't verify are shown as “Unknown” rather than guessed.

Field	Value
Repository	TPC-Council/HammerDB
Owner	TPC-Council
Primary language	Tcl
License	GPL-3.0 — OSI-approved
Stars	769
Forks	150
Open issues	14
Latest release	v6.0 (2026-06-26)
Last updated	2026-06-24
Source	https://github.com/TPC-Council/HammerDB

What HammerDB is

HammerDB is a Tcl-based benchmark harness supporting TPC-C (transaction processing) and TPC-H (analytical) workloads against multiple RDBMS backends. It generates repeatable synthetic load patterns, measures throughput/latency, and provides comparative metrics across database configurations and versions.

Quickstart

Get the HammerDB source

Clone the repository and explore it locally.

terminalbash

1git clone https://github.com/TPC-Council/HammerDB.git2cd HammerDB3# follow the project's README for install & configuration

Need it deployed, integrated, or customized instead? DEV.co ships production installs.

Best use cases

Database Performance Benchmarking

Evaluate raw throughput, latency, and scalability of production databases before migration or upgrade decisions using standardized TPC workloads.

Capacity Planning & Hardware Sizing

Run controlled OLTP and OLAP workloads to determine required CPU, memory, and I/O resources for anticipated production loads.

Multi-Database Comparison

Standardized testing across Oracle, SQL Server, Db2, PostgreSQL, MySQL, and MariaDB using identical TPC scenarios for informed platform selection.

Implementation considerations

Tcl language barrier: Engineers must be comfortable with Tcl scripting to customize workloads beyond stock TPC templates.
Database-specific setup: Each target DB (Oracle, SQL Server, Db2, PostgreSQL, MySQL, MariaDB) may require different client libraries, network configuration, and schema initialization steps.
Resource overhead: Benchmarking can consume significant CPU, memory, and I/O. Isolate test environments to avoid interfering with production systems.
Data volume scaling: TPC-H/TPC-C scale factors must be chosen to avoid caching artifacts; undersized datasets may mask real bottlenecks.
Result interpretation: Raw metrics (TPS, latency percentiles) require baseline context, statistical rigor, and domain knowledge to inform decisions.

When to avoid it — and what to weigh

Real-world Workload Simulation Required — HammerDB provides synthetic benchmarks, not actual application query patterns. If your workload is highly specialized or atypical, results may not reflect production behavior.
GPL-3.0 Commercial Restrictions — GPL-3.0 license requires derivative works to be open-source. If your organization cannot accept copyleft obligations or requires proprietary benchmarking tools, consider alternatives.
Automated/Scheduled Benchmarking Without Review — HammerDB requires manual setup, configuration, and result interpretation. Unsuitable for fully automated CI/CD pipelines without custom wrapper scripts and governance.
NoSQL, Columnar, or Emerging Database Support — HammerDB focuses on traditional SQL RDBMSes. If benchmarking modern data warehouses, time-series DBs, or NoSQL stores, this tool offers limited coverage.

License & commercial use

HammerDB is licensed under GNU General Public License v3.0 (GPL-3.0). This is a copyleft license requiring any derivative works or modifications to remain open-source and distribute source code. The tool itself may be used freely, but redistribution or commercial bundling of modified versions triggers GPL obligations.

Commercial use of unmodified HammerDB for benchmarking is permitted. However, GPL-3.0 is a copyleft license: if your organization modifies HammerDB or bundles it with proprietary software, you must open-source those modifications and derived works. Proprietary wrapper scripts, result parsers, or test harnesses built on top of unmodified HammerDB may face interpretation disputes. Requires review by legal/compliance before enterprise adoption.

DEV.co evaluation signals

Editorial assessment — not user reviews. Directional, with an explicit confidence level.

Signal	Assessment
Maintenance	Active
Documentation	Adequate
License clarity	Clear
Deployment complexity	Moderate
DEV.co fit	Good
Assessment confidence	High

Security considerations

HammerDB connects directly to production (or staging) database instances with plaintext or encrypted credentials. Secure credential storage, network segmentation, and audit logging are operator responsibilities. Tcl codebase should be reviewed if customizing workloads. No security audit, vulnerability disclosure policy, or CVE history stated in provided data.

Alternatives to consider

SysBench

Open-source (GPL-2.0), covers MySQL, PostgreSQL, Oracle; simpler CLI, lower friction for quick OLTP benchmarks. Less comprehensive than HammerDB; limited OLAP support.

TPCC-MySQL / tpch-gen

Lightweight, database-specific TPC implementations (e.g., TPCC for MySQL). Minimal overhead; easier to integrate into custom test scripts. Narrower scope than HammerDB.

Proprietary vendors (Oracle Real Application Testing, SQL Server Data Tools)

Native, supported benchmarking suites for each database. Higher cost, but vendor-backed; often more accurate production simulation for that specific DB.

Software development agency

Build on HammerDB with DEV.co software developers

HammerDB is ideal for capacity planning, performance validation, and multi-database comparison using standardized TPC benchmarks. However, ensure GPL-3.0 compliance and Tcl expertise before enterprise adoption. Contact us to assess fit and plan a proof-of-concept.

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HammerDB FAQ

Can I use HammerDB to benchmark my proprietary database fork?

Only if that fork remains open-source or you do not redistribute HammerDB modifications. Proprietary forks require custom adaptation; check GPL-3.0 compatibility with your legal team.

What programming background is needed to use HammerDB?

Basic familiarity with CLI, SQL, and database configuration. Advanced workload customization requires Tcl proficiency. No prior experience needed for out-of-the-box TPC-C and TPC-H runs.

Does HammerDB include result visualization or historical trending?

Not clearly stated in provided data. Likely CSV/text output; external tools (e.g., Excel, custom Python scripts) typically required for charts and trending.

Can I benchmark cloud-managed databases (RDS, Cloud SQL, Azure Database)?

Yes, provided network connectivity (VPN, security groups) allows HammerDB client to reach the database. No native cloud-specific integrations mentioned; standard JDBC/ODBC connection required.

Software development & web development with DEV.co

Adopting HammerDB is usually one piece of a larger software development effort. As a software development agency, DEV.co provides software development services and web development expertise — pairing senior software developers and web developers with your team to design, build, and operate open-source databases software in production.

Evaluate HammerDB for Your Database Testing Needs

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