StackOverflow data to postgres

This is a quick script to move the Stackoverflow data from the StackExchange data dump (Sept '14) to a Postgres SQL database.

Schema hints are taken from a post on Meta.StackExchange and from StackExchange Data Explorer.

Dependencies

• lxml
• psychopg2

Usage

• Create the database stackoverflow in your database: CREATE DATABASE stackoverflow;
  • You can use a custom database name as well. Make sure to explicitly give it while executing the script later.
• Move the following files to the folder from where the program is executed: Badges.xml, Votes.xml, Posts.xml, Users.xml, Tags.xml.
  • In some old dumps, the cases in the filenames are different.
• Execute in the current folder (in parallel, if desired):
  • python load_into_pg.py Badges
  • python load_into_pg.py Posts
  • python load_into_pg.py Tags (not present in earliest dumps)
  • python load_into_pg.py Users
  • python load_into_pg.py Votes
  • python load_into_pg.py PostLinks
  • python load_into_pg.py PostHistory
  • python load_into_pg.py Comments
• Finally, after all the initial tables have been created:
  • psql stackoverflow < ./sql/final_post.sql
  • If you used a different database name, make sure to use that instead of stackoverflow while executing this step.
• For some additional indexes and tables, you can also execute the the following;
  • psql stackoverflow < ./sql/optional_post.sql
  • Again, remember to user the correct database name here, if not stackoverflow.

Caveats and TODOs

• It prepares some indexes and views which may not be necessary for your analysis.
• The Body field in Posts table is NOT populated by default. You have to use --with-post-body argument to include it.
• The EmailHash field in Users table is NOT populated.

Sept 2011 data dump

• The tags.xml is missing from the data dump. Hence, the PostTag and UserTagQA tables will be empty after final_post.sql.
• The ViewCount in Posts is sometimes equal to an empty value. It is replaced by NULL in those cases.