Tkrzw

Paid LinuxMacSelf-hostedWindows

What Tkrzw is

Tkrzw is a free, Apache-2.0 C++ library implementing DBM for key-value records stored in files. It supplies file-backed hash, B+ tree, and skip-list databases, plus in-memory hash, B+ tree, cache, and standard-container options. A shared interface sets, retrieves, removes, and iterates records, and the database classes are documented as thread-safe for simultaneous access. Polymorphic, sharding, and asynchronous adapters extend the storage layer, while file and in-memory secondary indexes support lookup designs. Official bindings cover Python, Java, Ruby, and Go alongside C++. Python requires version 3.6 or later and prior Tkrzw installation; Java requires JDK 9 or later and prior installation. HashDBM documents ZLib, ZStd, LZ4, and LZMA compression, with RC4 and AES cipher options. Linux, macOS, Windows, and self-hosted deployments are supported. Unix-like builds use GCC 7.3 or later or Clang and GNU make; Windows builds use Visual Studio 2019 with C++ components. Open databases must be explicitly closed to avoid corruption.

Who it suits

Tkrzw suits developers building embedded or self-hosted key-value storage in C++ or its supported language bindings. It is appropriate when file-backed and in-memory database structures are needed.

What it does well

Multiple file-backed and in-memory database types
Thread-safe classes for simultaneous access
Python, Java, Ruby, and Go bindings
Secondary indexes and database adapters included
Compression and AES or RC4 options documented

What to know first

Python binding requires Python 3.6 or later
Java binding requires JDK 9 or later
Tkrzw must be installed before language bindings
Opened databases must be explicitly closed

Verdict

Tkrzw provides a broad DBM toolkit with several storage structures, adapters, indexes, and language interfaces. Build prerequisites and careful database closing are important operational considerations.

Facts from Tkrzw's own pages

Build tools: The README specifies GCC 7.3 or later, Clang, GNU make, and standard tools for Unix-like builds, and Visual Studio 2019 with C++ components for Windows builds. · github.com, 8 Oct 2026
Compression and encryption: HashDBM documents record compression options ZLib, ZStd, LZ4, and LZMA, and cipher options RC4 and AES. · dbmx.net, 8 Oct 2026
Concurrency: The API documentation says all database classes are thread-safe for simultaneous access by multiple threads. · dbmx.net, 8 Oct 2026
Core operations: The shared database interface supports setting, retrieving, and removing records, and iterating through records. · dbmx.net, 8 Oct 2026
Data structures: It provides file based hash, B+ tree, and skip list databases, plus several in-memory database implementations. · dbmx.net, 8 Oct 2026
Indexes: Tkrzw includes file and in-memory secondary index implementations and adapters. · dbmx.net, 8 Oct 2026
Indexes and adapters: The library includes polymorphic and sharding database adapters, an asynchronous adapter, and file and in-memory secondary index implementations. · dbmx.net, 8 Oct 2026
Java requirement: The Java binding documentation requires JDK 9 or later and says to install Tkrzw beforehand. · dbmx.net, 8 Oct 2026
Language bindings: Official documentation pages provide interfaces for Python, Java, Ruby, and Go in addition to the C++ library. · dbmx.net, 8 Oct 2026
License: The project repository identifies the license as Apache-2.0. · github.com, 8 Oct 2026
Operational requirement: Opened databases must be explicitly closed to avoid data corruption. · dbmx.net, 8 Oct 2026
Operations: The shared database interface supports setting, retrieving, and removing records, plus iterating through records. · dbmx.net, 8 Oct 2026
Platforms: The project README says Tkrzw is available on UNIX-like systems including Linux, Mac OS, FreeBSD, and Solaris, and on Windows. · github.com, 8 Oct 2026
Purpose: Tkrzw is a C++ library that implements DBM for storing key-value records in files. · dbmx.net, 8 Oct 2026
Python requirement: The Python binding requires Python 3.6 or later and requires Tkrzw to be installed first. · dbmx.net, 8 Oct 2026
Record protection options: HashDBM supports configurable record CRC checks and lists AES and RC4 cipher modes among its record compression options. · dbmx.net, 8 Oct 2026
Remote access: The separate Tkrzw-RPC project provides a server and gRPC library so multiple processes can access databases managed by the server. · dbmx.net, 8 Oct 2026
Storage types: It provides file-backed hash, B+ tree, and skip-list databases, as well as in-memory hash, B+ tree, cache, and standard-container databases. · dbmx.net, 8 Oct 2026
Support model: The repository provides contribution instructions and sample code, while the opened project pages do not state a commercial support offering. · github.com, 8 Oct 2026

Where Tkrzw stands on Freedom251

Embedded Databases#28 of 30