Re: Implementing SQL ASSERTION

Hi David,

> On 15 Jan 2018, at 16:35, David Fetter <david(at)fetter(dot)org> wrote:
>
> It sounds reasonable enough that I'd like to make a couple of Modest
> Proposals™, to wit:
>
> - We follow the SQL standard and make SERIALIZABLE the default
> transaction isolation level, and
>
> - We disallow writes at isolation levels other than SERIALIZABLE when
> any ASSERTION could be in play.

Certainly it would be easy to put a test into the assertion check function to require the isolation level be serialisable. I didn’t realise that that was also the default level as per the standard. That need not necessarily be changed, of course; it would be obvious to the user that it was a requirement as the creation of an assertion would fail without it, as would any subsequent attempts to modify the involved tables.

-Joe