Robert Haas wrote:
> An alternative approach is to have some kind of other identifier,
> let's call it a distributed transaction ID (DXID) which is mapped by
> each node onto a local XID.
Postgres-XL seems to manage this problem by using a transaction manager
node, which is in charge of assigning snapshots. I don't know how that
works, but perhaps adding that concept here could be useful too. One
critical point to that design is that the app connects not directly to
the underlying Postgres server but instead to some other node which is
or connects to the node that manages the snapshots.
Maybe Michael can explain in better detail how it works, and/or how (and
if) it could be applied here.
--
Álvaro Herrera https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services