most-inesctec / i2bplus-tree

:evergreen_tree: Improved Interval B+ tree implementation, in TS :evergreen_tree:

Improved Interval B+ tree implementation (I2B+ tree)

The Interval B+ tree (IB+ tree) is a valid-time indexing structure, first introduced by Bozkaya and Ozsoyoglu. This indexing structure appears as a time-efficient indexing structure for the management of valid-time/ intervals.

In this repository, we present the Improved Interval B+ tree (I2B+ tree), an indexing structure based on the IB+ tree, but with minor structural changes to improve the performance of the deletion operation. For a more detailed analysis of the I2B+ tree, refer to the paper published in the CISTI'2020 Conference, available at IEEE.

This structure performs all operations (insertion, search and deletion) with logarithmic performance (O (log n)). Documentation is available here.

Insertion	Range Search	Deletion

For an in-depth analysis of both the parameter tuning (such as the tree's order or the time-splits alpha value) and the conclusions obtained from the performance analysis of the I2B+ tree, check the benchmarks folder.

Usage

To suit the I2BplusTree to your needs, implement a class that extends the FlatInterval class, defining the information that will be stored on leaves there. One might also want to override the equals method, thus allowing the incorporation of the extra information stored in the Intervals in comparisons.

Example:

import { IBplusTree, FlatInterval } from 'i2bplustree';

// Create a class that inherits from the FlatInterval
class MyInterval extends FlatInterval {

    // This is just an example property
    // Like this there could be many more
    private myProperty: any;

    constructor(val1: number, val2: number, myPropertyValue: any) {
        super(val1, val2);
        this.myProperty = myPropertyValue;
    }

    // This is just an example method
    public exampleMethod(): void {
        // Do stuff
    }

    // Overriding equals method to take into account the new property
    equals(int: MyInterval): boolean {
        return this.upperBound == int.getUpperBound() &&
            this.lowerBound == int.getLowerBound() &&
            this.myProperty == int.getProperty();
    }
}

// Now we create our I2BplusTree object and insert a `MyInterval` object
const threshold = 30;
const alpha = 0.2;
const tree: IBplusTree<MyInterval> = new IBplusTree<MyInterval>(threshold, alpha);
// Introduce an object
tree.insert(new MyInterval(0, 2, "example-property"));

/**
And do many other operations such as:
- Delete an interval from the tree
- Delete all intervals contained in a range
- Verify if a interval exists in the tree
- Search all intervals with equal bounds to the ones provided
- Find the first interval that intersects the given bounds
- Find all intervals intersecting the given range
- Find all intervals contained in the given range
*/

Acknowledgements

This work was financed by the ERDF – European Regional Development Fund through the Operational Programme for Competitiveness and Internationalisation - COMPETE 2020 Programme and by National Funds through the Portuguese funding agency, FCT - Fundação para a Ciência e a Tecnologia within project PTDC/CCI-INF/32636/2017 (POCI-01-0145-FEDER-032636).

This work is also part of MOST.

Citation

E. Carneiro, A. V. d. Carvalho and M. A. Oliveira, "I2B+tree: Interval B+ tree variant towards fast indexing of time-dependent data," 2020 15th Iberian Conference on Information Systems and Technologies (CISTI), Sevilla, Spain, 2020, pp. 1-7, doi: 10.23919/CISTI49556.2020.9140897.

OR

Carneiro, Edgar, Alexandre Valle de Carvalho, and Marco Amaro Oliveira. "A Comparative Study on the Performance of the IB+ Tree and the I2B+ Tree." Journal of Information Systems Engineering and Management 6.3 (2021): em0142.

Acknowledgments

This work is financed by the ERDF – European Regional Development Fund through the Operational Programme for Competitiveness and Internationalisation - COMPETE 2020 Programme and by National Funds through the Portuguese funding agency, FCT – Fundação para a Ciência e a Tecnologia within project PTDC/CCI-INF/32636/2017 (POCI-01-0145-FEDER-032636).

i2bplus-tree's Issues

how to test it?

Iterate over all values

Is there a way to iterate over all values of the tree?

cc @EdgarACarneiro

Fix `equals` method not allowing override

The current implementation does not allow the overriding of the FlatInterval.equals method since internally some FlatInterval objects are created to optimise data handling. As such, if one does override the equals method with the new properties, the search method brakes.

Possible solutions:

• Stop creating FlatInterval objects inside the I2BplusTree and just use/ move around the valid times;
• Create a new method (e.g. intervalEquals) that just makes the comparison of the intervals. Then, this method is used for comparison with the FlatInterval objects inside the tree, while the equals method is used for comparison between objects introduced by the user.

Missing type definitions

Hi! :) It seems that version 1.0.1 is missing type definitions: