Howard Chu writes:
BTW, if back-bdb and dbpagesize measure pages in 1K block units, back-bdb must ensure Berkeley DB doesn't pick 512-byte blocks.
If you set an explicit size, BDB doesn't get to pick, so that's irrelevant.
OK. I was thinking the other way: If back-bdb reads the setting and makes use of it for something. I guess not.
Besides, no worthwhile filesystems in common use today use 512 byte blocks.
Famous last words... Next FS revolutions will see - oh, blocks of blocks where the inner blocks often are small. Or whatever.
Brainstorming a bit more: For a DB admin, I imagine it could be nice to allow "I don't care as long as you don't pick too small or too large pages". I.e. a pagesize range:
(...) Anyone who changes this setting should have read all of the relevant BDB docs first, to understand the risks and tradeoffs. At that point, they should choose a specific number, none of this fuzzy approximate range stuff.
Fine by me.