Virtual Machinerys BTree for Smalltalk is a set of classes which implement a BTree in Smalltalk. These classes give fast access to textually indexed data. Full source code and extensive documentation are provided for a number of Smalltalk platforms.
B-Trees are highly efficient data storage systems used by a number of operating systems and languages e.g. Novell, MUMPS. They provide rapid access to stored data using textual keys. The B-Tree presented here is in fact a B+Tree – this is distinguished from other B-Trees by its use of two files – one holds the indices and the other holds the indices and data. The index file is much smaller than the combined total of all the indices since it holds only the first index to each page in the index file.
Java and Smalltalk versions
Java version includes code for J2SE and J2ME (phones, Palm OS etc) platforms and for Read-Only BTrees (smaller footprint, faster performance)
Reliability – Virtual Machinery’s BTree product has been in use in Smalltalk and Java applications since 1990
Fast access to textually keyed data (sub-millisecond access on most platforms when index and data are fully cached).
Forward key compression allows use of meaningful keys with reduced space penalty.
Individual datasets can hold up to 4Gb of data.
Transaction support with commit and rollback
User defined cache levels for both index and data pages.
Smalltalk and Java versions use same file format allowing each to access datasets created by the other.
Design allows for single classes to be substituted e.g. to use a different type of cache.
Easily Extendable (even without source code)
Full documentation – programmers guide, modification guide, javadoc for public classes and interfaces
Demonstration applications supplied
Full source code available as an option (includes javadoc for all classes)
Single use, Site, corporate development and distribution licenses available
Commercial Distribution license allows distribution of applications built on Virtual Machinery’s BTree Technology
Extensive guide to the principals and use of BTrees – available here
Full guide to the use of the classes
Single process only.
Key limited to 120 bytes.
Maximum 64k data pages.
Maximum 65024 byte page size.
License options & pricing
Free Trials (J2ME, J2SE and J2EE) – available here
Java Base license without source code – $99.95/ €74.95
Smalltalk Base License (includes source code) – $149.95/ €119.95
Site Distribution License (requires Java or Smalltalk base license) – $149.95/ €119.95
Corporate Distribution License (requires Java or Smalltalk base license) – $249.95/ €199.95
Commercial Distribution License (requires Java or Smalltalk base license) – $199.95/ €149.95
Site Distribution License, Corporate Distribution License and Commercial Distribution License include 1 years email support (3 incidents) + 1 free update within year
Source code – Smalltalk distribution includes source code
Java BTree Base source code (requires Java Base license) – $149.95/ €119.95
Latest posts by Virtual Machinery(see all)
- JHawk Starter - April 20, 2015
- Virtual Machinery Indicators Base - December 10, 2014
- Virtual Machinery Indicator Creator Base + Commercial Distribution license - December 10, 2014