Re: [PATCH] Logical decoding of TRUNCATE

On 1/24/18 07:53, Petr Jelinek wrote:
> That depends on if we consider this to be part of sequence handling or
> truncate statement replication handling. It's true that if we had
> sequence replication, the restart would get propagated that way anyway.
> OTOH, if we'll want to add option in the future to propagate cascade (to
> any additional tables on downstream), it may need to reset sequences
> which are not even present upstream and as such would not be handled by
> sequence replication.

Logical replication, as it currently is designed, replicates discrete
actions, not commands. A delete command that deletes five rows and
cascades to delete three more rows somewhere else ends up being
replicated as eight changes. So I think a TRUNCATE command that
cascades to four tables and resets six sequences should end up being
replicated as ten changes. (Since we currently don't handle sequences
at all, we'll omit the six sequence changes for now.)

--
Peter Eisentraut http://www.2ndQuadrant.com/
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