Re: Potential GIN vacuum bug

Jeff Janes <jeff.janes@gmail.com> writes:

Your earlier point about how the current design throttles insertions to
keep the pending list from growing without bound seems like a bigger deal
to worry about.  I think we'd like to have some substitute for that.
Perhaps we could make the logic in insertion be something like

        if (pending-list-size > threshold)
        {
                if (conditional-lock-acquire(...))
                {
                        do-pending-list-cleanup;
                        lock-release;
                }
                else if (pending-list-size > threshold * 2)
                {
                        unconditional-lock-acquire(...);
                        if (pending-list-size > threshold)
                                do-pending-list-cleanup;
                        lock-release;
                }
        }

so that once the pending list got too big, incoming insertions would wait
for it to be cleared.  Whether to use a 2x safety margin or something else
could be a subject for debate, of course.