http://people.csail.mit.edu/jaffer/WB
	The WB B-Tree Database for SCM, Java, C#, C, and C++
	Current Version Released Terms 2b4 2020-02-16 LGPL

WB is a disk based (sorted) associative-array database package providing C, SCM, Java, and C# libraries. These associative arrays consist of variable length (0.B to 255.B) keys and values. Functions are provided to:

• create, destroy, open and close disk-files and associative arrays;
• insert, delete, retrieve, find next, and find previous (with respect to dictionary order of keys); and
• apply functions, delete, or modify values over a range of consecutive key values.

WB is thread safe (so long as HAND structures are not shared between threads). The `put' and `rem' operations allow associations to be used for thread mutexs.

The WB implementation has a file size limit of 2³² * block size (default 2048.B) = 2⁴³ bytes (8796.GB). WB does its own memory and disk management and maintains a RAM cache of recently used blocks. Multiple associative arrays can reside in one disk file. Simultaneous access to multiple disk files is supported.

The (database) disk files interoperate between the various language platforms. The interface to the SCM Scheme implementation supports longer data values and SLIB relational databases.

A structure checking and garbage collecting program and a block viewer are provided.

WB is lightweight; compiled on x64 GNU/Linux, the wb-2b4 library sizes are:

WB is implemented using a variant of B-tree structure. B-trees give slower access than hashing but are dynamic and provide an efficient determination of successor and predecessor keys. All operations are O(log(n)) in the size of the database. B-trees are commonly used by database systems for implementing index structures. B-trees are optimized for using the minimum number of disk operations for large data structures. Prefix and suffix key compression are used for storage efficiency in WB.

WB, SLIB, and SCM are GNU packages.

News

• scm2c, scm2cs, scm2java: Minor translator corrections.
• scm2c, segs.scm (bytes-length): The only 2 translated calls are in segs.scm. Translate them to strlen().
• c/segs.c, segs.scm: db-version-str and db-authors-str are strings, not bytes.
• c/Makefile: -lpthread must be after linked files.

Quick Start

• Obtain wb-2b4-1.i686.rpm (290.kB) or wb-2b4-1.x86_64.rpm (285.kB) and install; or
  obtain wb-2b4.zip (240.kB), build, and install.

Documentation

• Online WB Manual or wb.pdf
• Online Japanese WB Manual from Dai Inukai
• Using WB from C++ at AbiusX

WB Development

• Savannah: CVS Repository wb/wb
• Development Snapshot wb.zip (220.kB)
• WB discussion mailing list

Related Software

• SLIB Scheme Library
• SCM Scheme Implementation
• Schlep Toolchains: Producing compatible Java, C#, and C code.
• Water: a high-level persistant "databased" language built on WB.

Miscellany

• FTP Links to WB and related software from this site and mirrors.
• htmls.zip, a collection of these html documentation files (600.kB)