Re: Hot Standby (v9d)

Hannu Krosing <hannu@krosing.net> writes:

> Actually we came up with a solution to this - use filesystem level
> snapshots (like LVM2+XFS or ZFS), and redirect backends with
> long-running queries to use fs snapshot mounted to a different
> mountpoint.

Uhm, how do you determine which snapshot to direct the backend to? There could
have been several generations of tuples in that tid since your query started.
Do you take a snapshot every time there's a vacuum-snapshot conflict and
record which snapshot goes with that snapshot?

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