tinydb

Query Optimization Course

Quickstart

1. Run make to compile the source code.
2. Run make db to create a sample database inside the data directory.

Query execution

The query execution logic can be found in src; test it using e.g.

bin/query data/uni "SELECT v.titel
  FROM studenten s, hoeren h, vorlesungen v
  WHERE s.matrnr=h.matrnr
  AND h.vorlnr=v.vorlnr
  AND s.name='Carnap'"

This should give the following output:

Ethik
Wissenschaftstheorie
Bioethik
Der Wiener Kreis

Query graph & join tree

Basically, query graph and join tree will be generated and shown when using EXPLAIN instead of SELECT in SQL queries.

To generate an image file, the circo and dot executables provided by graphviz are needed. Also ImageMagick's display command is required.

Test it using e.g.

bin/query data/uni "EXPLAIN * FROM studenten s, hoeren h, vorlesungen v WHERE s.matrnr=h.matrnr AND v.vorlnr=h.vorlnr"

Exercises

Exercise 1

The source code is located in exercises/ex01. Execute the code using bin/ex01-query1 and bin/ex01-query2.

Exercise 5

1. Execute make tpch-db to fetch TPC-H data (7zip is required) and create a database.
2. Run bin/ex05-query.sh to execute the exercise query. It runs the query using EXPLAIN, so query graph and join tree will be shown.

Exercise 7

To generate Dyck words, execute e.g. bin/dyck 7 56. This will generate the Dyck word from the exercise session 7 example, "(((())())(()))".