LDB

LDB version 0.6 is an object-oriented database management system built on top of SHORE 3.0. It supports ODMG ODL specifications and can handle most ODMG OQL queries (but it is not fully ODMG-compliant yet). Please send your comments and report any bugs to fegaras@cse.uta.edu.

Highlights:

• The front-end:
  • can handle most ODL declarations;
  • can process most OQL queries;
  • supports embedded OQL in C++ with low impedance mismatch;
  • supports light-weight C++ and Java interfaces;
  • provides a visual query formulation interface;
  • supports transactions, updates, index creation & maintenance, macros, functions, and methods with OQL body;
  • extends OQL with XPath syntax to query XML data.
• The query optimizer:
  • unnests all nested (correlated) queries;
  • can materialize path expressions into pointer joins;
  • performs semantic optimizations using ODL relationships;
  • uses a cost-based polynomial-time heuristic for join ordering;
  • uses a rule-based cost-driven optimizer to produce physical plans.
• The query evaluator:
  • has two modes: translates evaluation plans into C++ code at compile-time or interprets the plans at run-time;
  • supports stream-based processing (it materializes streams only when necessary);
  • supports many evaluation algorithms, including sorting, block nested loop, indexed nested loop, pointer join, and sort-merge join;
  • supports the creation, maintenance, and use of indexes.

• Overview: Everything you always wanted to know about LDB but were afraid to ask.
• Installation: How to install LDB.
• User's Guide: How to use LDB.
• Voodoo: The visual query formulation for LDB.
• System Guide: If you want to understand the internals and extend the system.
• Status: Current status, bugs, problems, and to-do list.
• Lambda-DB: The old Lambda-DB system based on SHORE 1.1.1.

Copyright © 1999-2004 by Leonidas Fegaras, the University of Texas at Arlington. All rights reserved.
This material is provided as is, with absolutely no warranty expressed or implied. Any use is at your own risk.
Permission is hereby granted to use or copy this program for any purpose, provided the above copyright notice is retained on all copies. See the README file in the distribution for more details. This work was supported in part by the National Science Foundation under grant IIS-9811525. The theoretical framework of this system was developed by Leonidas Fegaras and David Maier. The implementation was done by Leonidas Fegaras and by UTA students.