Virtual Machinery Btree

Virtual Machinery Btree Version 6 build 101

Standard Single user License - No source codeIncludes standard...

Standard Single user License - No source codeIncludes standard jar files for J2SE, J2EE and J2ME environments and full documentation. Licensed for individual use on any one computer.

Distribution of the jar is not allowed with the base license - this requires an additional Distribution license - Site, Corporate and Commercial distribution licenses are available.

Virtual Machinerys BTree is a set of classes which implement a BTree in Java. These classes give fast access to textually indexed data. Full source code and extensive documentation are provided.

Versions are also available for a number of Smalltalk platforms. Virtual Machinery's BTree classes for J2ME add micro-footprint functionality to your BTree.

Using Sun's Wireless Toolkit application BTrees can be built for small footprint devices (such as Phones and PDAs). In both J2SE and J2ME environments a set of classes is provided which implements read-only BTrees , reducing memory footprint and increasing performance.

BTree jars provided and size -BTreeRO. jar 25kBTreeRMSRO. jar 26kBTreeMERO. jar 28kBTree. jar 38kBTreeRMS. jar 39kBTreeME. jar 39k 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.

Main Features- Java and Smalltalk versionsJava 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 1990Fast 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 rollbackUser 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 interfacesDemonstration applications suppliedFull source code available as an option (includes javadoc for all classes)Single use, Site, corporate development and distribution licenses availableCommercial Distribution license allows distribution of applications built on Virtual Machinery's BTree TechnologyJ2ME VersionBtree implemented using RMS as underlying data storage mechanism.

Allows persistence on devices which support RMS. Equivalent to 'persistent HashMap'The BTree overcomes the limitations of the RMS - particularly on indexingAlso use ofin-memory BTrees to allow functionality on 'disconnected' devicesDemonstration applications for Sun Wireless Toolkit, Nokia Developer Toolkit and Palm OSDocumentationInstallation guideExtensive guide to the principals and use of BTrees - available hereFull guide to the use of the classes (including javadoc).

Virtual Machinery Btree


Virtual Machinery Btree Version 6 build 101