Cdb-library Version 2.6 Final Guide

mkdir build && cd build cmake -DCMAKE_BUILD_TYPE=Release .. make && sudo make install Package maintainers: The tarball signature ( cdb-2.6.tar.gz.asc ) is signed with Michael Tokarev’s GPG key (fingerprint B3A5 1F17 045E 3C6A 0DC3 D96A A7C4 F6B6 6B2C 476F ). The maintainers have announced that 2.6 final will be the last feature release of the original cdb-library . From here, only security patches and critical bug fixes will be backported. Why? Because the format has reached perfection for its use case: extremely fast reads, atomic replacement via cdb_make , and zero runtime dependencies .

| Operation | CDB 2.5 | CDB 2.6 final | GDBM 1.23 | LevelDB (read only) | |-----------|---------|---------------|-----------|---------------------| | Sequential write (build) | 11.2 sec | 10.8 sec | 18.4 sec | 24.1 sec | | Random lookup (cache cold) | 0.8 µs | 0.8 µs | 2.3 µs | 1.9 µs | | Random lookup (hot cache) | 0.12 µs | 0.12 µs | 0.45 µs | 0.3 µs | | Memory footprint (idle) | ~8 KB | ~8 KB | 2.1 MB | 15 MB | cdb-library version 2.6 final

This isn’t just another maintenance release. It’s a quiet revolution for those who value predictability over complexity . First, a quick refresher. CDB was originally designed by Daniel J. Bernstein in the late 1990s for his qmail and djbdns suites. The format is deceptively simple: a binary file with three sections—a fixed-size hash table, a series of data pointers, and the actual key/value data. Lookups are deterministic, requiring at most two disk accesses. There are no locks, no transactions, and no unnecessary overhead. mkdir build && cd build cmake -DCMAKE_BUILD_TYPE=Release

The cdb-library (often referred to as libcdb ) is the reference implementation, written in portable C. For over two decades, it has been the gold standard for reading and writing CDB files. From here, only security patches and critical bug

Have you used CDB in production? Found a surprising use case? Let us know in the comments below or on the cdb-library mailing list.