From Fedora Project Wiki
  • LMDB
    • Written in: C
    • Wrappers for: C++, Java, Python, Perl, Ruby, Go, Erlang, PHP, Lua
    • Packages available for: Fedora 23+, EPEL6+
    • License:
    • Search key length:
    • Read-only access to DB:
    • Supported architectures:
    • Query keys larger than X:
  • Kyoto Cabinet (replacing Tokyo Cabinet)
    • Written in: C++
    • Wrappers for: C, Java, Python, Ruby, Perl, and Lua
    • Packages available for: Fedora 23+, EPEL5+
    • License:
    • Search key length: No limit from database itself (uses c++ std::string or combination of c-style string and its length).
    • Read-only access to DB: See http://fallabs.com/kyotocabinet/spex.html, part Sharing One database by Multiple Processes. TL;DR: One DB cannot be accessed by multiple processes, DB file is protected by reader-writer lock (which means it will probably require write access even for read-only operation).
    • Supported architectures: Linux 2.6 and later (i386/x86-64/PowerPC/Alpha/SPARC)
    • Query keys larger than X: DB supports matching by regex, which should be possible to use for this kind of query. Other possibilities are match by prefix and match by similarity.
  • LevelDB
    • Written in: C++
    • Wrappers for: Java, Go, Erlang, node.js
    • Packages available for: Fedora 23+, EPEL6+
    • License:
    • Search key length:
    • Read-only access to DB:
    • Supported architectures:
    • Query keys larger than X:
  • RocksDB (Built on LevelDB)
    • Written in:
    • Wrappers for:
    • Packages available for: Not available in Fedora?
    • License:
    • License:
    • Search key length:
    • Read-only access to DB:
    • Supported architectures:
    • Query keys larger than X:
  • UnQlite
    • Written in: C
    • Wrappers for:
    • Packages available for: Not yet available in Fedora
    • License:
    • Search key length:
    • Read-only access to DB:
    • Supported architectures:
    • Query keys larger than X:

Older (possibly unmantained) projects

  • TokyoCabinet (replacing QDBM)
    • Written in: C
    • Wrappers for: Perl, Ruby, Java, and Lua
    • Packages available for: Fedora 23+, EPEL5+, RHEL6+
    • License:
    • Search key length:
    • Read-only access to DB:
    • Supported architectures:
    • Query keys larger than X:
  • QDBM
    • Written in: C
    • Wrappers for: C++, Java, Perl, and Ruby
    • Packages available for: Fedora 23+
    • License:
    • Search key length:
    • Read-only access to DB:
    • Supported architectures:
    • Query keys larger than X:
  • NDBM
    • Written in:
    • Wrappers for:
    • Packages available for:
    • License:
    • Search key length:
    • Read-only access to DB:
    • Supported architectures:
    • Query keys larger than X:
  • GDBM
    • Written in:
    • Wrappers for:
    • Packages available for:
    • License:
    • Search key length:
    • Read-only access to DB:
    • Supported architectures:
    • Query keys larger than X: