Support the new RawFileDiffData migration in condensediffs.
Review Request #6227 — Created Aug. 13, 2014 and submitted — Latest diff uploaded
condensediffs has been updated to handle the migration of
LegacyFileDiffData entries to RawFileDiffData. A lot of work went into
optimizing this. These are converted in batches, with minimal SQL
queries on a modern database (read: not sqlite3).A run of condensediffs on a copy of a real-world database containing
650,000 diffs (all stored in LegacyFileDiffData entries) took 15 minutes
to convert, with a space savings of 80% (3.6GB down to 714MB).
Ran this many, many times without problems.
This was tested on sqlite, MySQL, and PostgreSQL.