Hive Thought Rewriter

The library rewrites different RSP-QL queries to either combine or decompose.

Usage

Installation

npm install hive-thought-rewriter

Rewriting Queries by Combining

Different queries in RSP-QL [1] query format can be specified and combined together to create a single RSP-QL query.

import {QueryCombiner} from "hive-thought-rewriter";

const combiner = new QueryCombiner();

combiner.addQuery(query1);
combiner.addQuery(query2);

const combined = combiner.combine();
/**
 * This will return the RSPQL query and it's different components 
 * in a object with type Parsed Query
 * 
 * To get the query in string format
 */

const combined_query_string = combiner.ParsedToString(combined);

Rewriting Queries by Decomposing

This is currently not possible and is a work in progress.

Rewriting the Queries by changing the Window Parameters

import {RewriteChunkQuery} from "hive-thought-rewriter";

// Define the new window parameters for the query i.e slide is 10 and width is 20

const chunkRewriter = new RewriteChunkQuery(10, 20);

const originalQuery = `PREFIX ex: <http://example.org/>
            REGISTER RStream <output> AS
            SELECT (AVG(?age) AS ?averageAge)
            FROM NAMED WINDOW ex:w ON STREAM ex:stream [RANGE 10 STEP 5]
            WHERE {
                WINDOW ex:w {
                    ?person a ex:Employee.
                    ?person ex:hasAge ?age.
                }
            }`;

const rewrittenQuery = chunkRewriter.rewrite(originalQuery);
/**
 * This will return the RSPQL query with the new window parameters as a string
 */

License

This code is copyrighted by Ghent University - imec and released under the MIT Licence

Footnotes

[1]: RSP-QL Semantics: A Unifying Query Model to Explain Heterogeneity of RDF Stream Processing Systems