Neil Conway <neilc(at)samurai(dot)com> writes:
> However, I don't really like the idea of blocking the backend for a
> potentially significant amount of time in a state half-way between
> "committed" and "ready for the next query".
I wonder whether we could use something comparable to pg_multixact
or pg_subtrans, to convert the problem from one of "need to fit in
fixed amount of memory" to one of "it's on disk with some buffers
in memory".
regards, tom lane