Do we know for sure if gitlab cloud uses a multi-tenanted database, or a db per user/customer/org? …

> For example, Github had 128 million public repositories in 2020. Even with 20 issues per repository it will cross the serial range. Also changing the type of the table is expensive. I expect the majority of those public repositories are forks of other repositories, and those forks only exist so someone could create pull requests against the main repository. As such, they won't ever have any issues, unless someone makes a mistake. Beyond that, there are probably a lot of small, toy projects that have no issues at all, or at most a few. Quickly-abandoned projects will suffer the same fate. I suspect that even though there are certainly some projects with hundreds and thousands of issues, the average across all 128M of those repos is likely pretty small, probably keeping things well under the 2B limit. Having said that, I agree that using a 4-byte type (well, 31-bit, really) for that tab…