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PGExercises

Steve Bang edited this page Aug 9, 2019 · 8 revisions

PgExercises is a sample dataset used to power the PostgreSQL Exercises tutorial website. The site is comprised of over 80 exercises designed to be used as a companion to the official PostgreSQL documentation. The exercises on the PGExercises site range from simple SELECT statements and WHERE clauses, through JOINs and CASE statements, then on to aggregations, window functions, and recursive queries.

The dataset consists of 3 tables (members, bookings, and facilities) and table relationships as shown in the ER diagram below:

Download and Install YugaByte DB

The latest instructions on how to get up and running are on our Quickstart page here:

https://docs.yugabyte.com/latest/quick-start/

Download and Install the PGExercises Database

Download the PGExercises Scripts

You can download the PGExercises database that is compatible with YugaByte DB from our GitHub repo. The two files are:

Create the Exercises Database

CREATE DATABASE exercises;

Let’s confirm we have the exercises database by listing out the databases on our cluster.

postgres=# \l

Switch to the exercises database.

postgres=# \c exercises
You are now connected to database "exercises" as user "postgres".
exercises=#

Build the Exercises Tables and Objects

exercises=# \i /Users/yugabyte/clubdata_ddl.sql

We can verify that all 3 of our tables have been created by executing:

exercises=# \d

Load Sample Data into Exercises

Next, let’s load our database with sample data.

exercises=# \i /Users/yugabyte/clubdata_data.sql

Let’s do a simple SELECT to pull data from the bookings table to verify we now have some data to play with.

exercises=# SELECT * FROM bookings LIMIT 5;

Try the PGExercises Tutorial

That’s it! You are ready to start working through the PGExercises tutorial with YugaByte DB as the backend. PGExercises is made up of 81 exercises and broken into the following major sections:

Note that all of the exercises on the site will work with YugaByte DB with the exception of the following:

  • This JOIN example has a bug and won’t return the correct row numbers. The GitHub issue can be tracked here.
  • In this string operation exercise you might notice that our sort order will be different. This is because we hash partition our data. As a result, row ordering is expected to be different.
  • In the calculated UPDATE example, you will get an error because “FROM clause in UPDATE” is not yet supported. You can track the issue on GitHub here.
  • The exercise which demonstrates a DELETE based on a subquery will return an error. You can track the resolution of this issue on GitHub here.