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GHA build status Coverity Scan Build Status Coverage Status PMEMKV version Packaging status

pmemkv is a local/embedded key-value datastore optimized for persistent memory. Rather than being tied to a single language or backing implementation, pmemkv provides different options for language bindings and storage engines.

For more information, including C API and C++ API see: Documentation is available for every branch/release. For most recent always see (master branch):

Latest releases can be found on the "releases" tab.

Up-to-date, current support/maintenance status of branches/releases is available on

There is also a small helper library pmemkv_json_config provided. See its manual for details.

Table of contents

  1. Installation
  2. Language Bindings
  3. Storage Engines
  4. Benchmarks
  5. Contact us


Installation guide provides detailed instructions how to build and install pmemkv from sources, build rpm and deb packages and explains usage of experimental engines and pool sets.

Language Bindings

pmemkv is written in C/C++ and can be used in other languages - Java, Node.js, Python, and Ruby.


C/C++ Examples

Examples for C and C++ can be found within this repository in examples directory.

Other Languages

The above-mentioned bindings are maintained in separate GitHub repositories, but are still kept in sync with the main pmemkv distribution.

Storage Engines

pmemkv provides multiple storage engines that share common API, so every engine can be used with all language bindings and utilities. Engines are loaded by name at runtime.

Engine Name Description Experimental Concurrent Sorted Persistent
cmap Concurrent hash map No Yes No Yes
vsmap Volatile sorted hash map No No Yes No
vcmap Volatile concurrent hash map No Yes No No
csmap Concurrent sorted map Yes Yes Yes Yes
radix Radix tree Yes No Yes Yes
tree3 Persistent B+ tree Yes No No Yes
stree Sorted persistent B+ tree Yes No Yes Yes
robinhood Persistent hash map with Robin Hood hashing Yes Yes No Yes

The production quality engines are described in the libpmemkv(7) manual and the experimental ones are described in the file.

pmemkv also provides testing engines, which may be used in unit tests or for benchmarking application overhead

Engine Name Description Experimental Concurrent Sorted Persistent
blackhole Accepts everything, returns nothing No Yes No No
dram_vcmap Volatile concurrent hash map placed entirely on DRAM Yes Yes No No

Contributing a new engine is easy, so feel encouraged!


Experimental benchmark based on leveldb's db_bench to measure pmemkv's performance is available here: (previously pmemkv-tools).

Contact us

For more information about pmemkv, contact Igor Chorążewicz (, Piotr Balcer ( or post on our #pmem Slack channel using this invite link or Google group.