Key/Value Datastore for Persistent Memory
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, see https://pmem.io/pmemkv.
Latest releases can be found on the "releases" tab. Up-to-date support/maintenance status of branches/releases is available on pmem.io.
The C++ API of pmemkv is documented in the Doxygen documentation listed below:
There is also a small helper library pmemkv_json_config provided.
See its manual for details.
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.
- Building from Sources
- Installing on Fedora
- Installing on Ubuntu
- Using Experimental Engines
- Building packages
- Using a Pool Set
pmemkv is written in C/C++ and it is used by bindings for Java, Node.js,
Python, and Ruby applications.
Examples for C and C++ can be found within this repository in examples directory.
Abovementioned bindings are maintained in separate GitHub repositories, but are still kept
in sync with the main pmemkv distribution.
- Java - https://github.com/pmem/pmemkv-java
- + Java Native Interface - https://github.com/pmem/pmemkv-jni
- Node.js - https://github.com/pmem/pmemkv-nodejs
- Python - https://github.com/pmem/pmemkv-python
- Ruby - https://github.com/pmem/pmemkv-ruby
pmemkv provides multiple storage engines that conform to the same 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? |
|---|---|---|---|---|
| blackhole | Accepts everything, returns nothing | No | Yes | No |
| cmap | Concurrent hash map | No | Yes | No |
| vsmap | Volatile sorted hash map | No | No | Yes |
| vcmap | Volatile concurrent hash map | No | Yes | No |
| tree3 | Persistent B+ tree | Yes | No | No |
| stree | Sorted persistent B+ tree | Yes | No | Yes |
| caching | Caching for remote Memcached or Redis server | Yes | No | - |
The production quality engines are described in the libpmemkv(7) manual and the experimental engines are described in the ENGINES-experimental.md file.
Contributing a new engine is easy and encouraged!
Benchmarks' scripts and other helpful utilities are available here: