1 cdb is a fast, reliable, lightweight package for creating and reading
2 constant databases. Its database structure provides several features:
4 * Fast lookups: A successful lookup in a large database normally takes
5 just two disk accesses. An unsuccessful lookup takes only one.
6 * Low overhead: A database uses 2048 bytes, plus 24 bytes per record,
7 plus the space for keys and data.
8 * No random limits: cdb can handle any database up to 4 gigabytes. There
9 are no other restrictions; records don't even have to fit into memory.
10 Databases are stored in a machine-independent format.
11 * Fast atomic database replacement: cdbmake can rewrite an entire
12 database two orders of magnitude faster than other hashing packages.
13 * Fast database dumps: cdbdump prints the contents of a database in
14 cdbmake-compatible format.
16 cdb is designed to be used in mission-critical applications like e-mail.
17 Database replacement is safe against system crashes. Readers don't have
18 to pause during a rewrite.
20 Note for developers: packages that need to read cdb files should
21 incorporate the necessary portions of the cdb library rather than
22 relying on an external cdb library. (See WWW)
24 WWW: http://cr.yp.to/cdb.html