For a lot of "one off" tasks (like analyzing a big log file), just configuring a full blown DBMS like MySQL or Postgres would take longer than it would to write

For a lot of "one off" tasks (like analyzing a big log file), just configuring a full blown DBMS like MySQL or Postgres would take longer than it would to write a script using an in memory SQLite DB and running the necessary queries. I'm not sure MySQL and Postgres are faster enough to justify the extra setup work when everything fits in memory. My intuition is that they may even be slower, because they still have to write everything to disk, where SQLite can be memory only.