It's not so much a question - but I'd be interested to hear any thought.
On our large, clustered site we had to reset our Dashboard to default for all users which we did yesterday. It's taken c. 20 hours to complete. Given the number of users I can live with that. However, the transaction (I assume) in that process played havoc with table locking through this time. The tables involved (context, my-pages, user-preferences) all became "unstable" and gave constant transaction timeouts for any activity involving them. For example, it was no longer possible to delete blocks anywhere on the site.
This has "fixed itself" on completion of the Dashboard reset but I thought I'd mention it as it was rather alarming. Also, does anybody have any thoughts about what went wrong?