Is it normal for mediawiki database dumps (using mysqldump) to become smaller over time while the wiki content is strictly growing (i.e. nothing is being deleted)? Or is something wrong with my backup script?
Topic on Project:Support desk
That does seem odd. What does your backup script look like?
The essence of it is
mysqldump -h localhost -u user -pxxxx mediawikidb | bzip2 > yyyy.sql.bz2
I made sure to compare the uncompressed sizes...
Some data is deleted. Things that come to my mind:
- Old recent changes
- Cached data (object cache, parser cache, resource loader cache), specially during an upgrade, the tables storing this data may be truncated.
- Jobs: Completed jobs get deleted
- Watchlist configuration: in case some accounts had a lot of pages in their watch lists and they clear their watch lists (but unlikely to be noticeable)