This project was initially written for my Database Sytems Implementation exam. It's a small database engine supporting recursive queries of the following type:
WITH RECURSIVE t(c1, c2) AS (
SELECT * FROM a
UNION
SELECT a.c1, t.c2 FROM a, t WHERE t.c1 = a.c2 AND t.c2 > t.c1 AND a.c2 > a.c1
)
SELECT * INTO n FROM t;I have provided two ways of execution for them (a straightforward algorithm, "StandardDB", and an optimised one, "RecursiveDB").
The engine can be customised from the config.js file, where different parameters can be changed (details in file).
The exact type of syntax that can be parsed can be seen in the dataset\query1.txt, dataset\query2.txt and dataset\queryOrdered.txt files . No other keywords than those is the example files are supported, but tables can have any number of columns and the recursive instruction can have any number of comparison operations.
To see how to use the the db engine and how to write your own benchmarks, take a look at index.js, graphBenchmark.js and orderedBenchmark.js in the root folder.
Node.js and NPM are installed.
Another assumption is that the code will run on a Linux-like console due
to the way environment variables are set through the npm commands in package.json.
Before running the code, download all the dependencies from npm:
npm install
The database has configurable properties such as the amount of records a page can store or how long it takes to retrieve one. You can modify all this in the config.js file in the root folder.
To run the code on the datasets and queries given with the exam, run the following command:
npm run benchmark -- --batchNumber 1 --queryNumber 1
You can replace the 1s with the batch number and query number you desire (batches: 1-3, queries: 1-2). The command will run the selected query on the selected dataset with both the StandardDB and RecursiveDB algorithms.
Run the following command:
npm run graph -- --n 1000
You can replace the 1000 with the number of nodes you want the generated graphs to have. For details about what these implies, see project report.
Run the following command
npm run order
Important: the scales variable in the config.js file will
represent the number of entries generated, not a percentage.
After running any of the above commands, when the timing of the operations finishes a server will be started at port 8991 on localhost, serving the generated time plot. To view it go to http://localhost:8991/plots/0/index.html. The link should open automatically in a browser tab once all the processing is done, but if it does not just copy-paste it into the browser.