max value for rev_id in the revision table

[dmcmilla]

The method to get the next rev_id doesn't always match the next value that will be inserted in the revision table. The revision table uses a sequence to insert the next row. In the case where a record was deleted, max +1 would not equal the next sequence # of the rev_id. It's probably not an issue on a fresh system or one where no deletes have been performed.

[shigapov]

Right! The main focus was indeed on a fresh Wikibase instance, without deleted entities in mind.