Right, I'm not so familiar with it but from that page:
> The replication mechanism is based on logical decoding and an earlier version of the pglogical extension provided for community by the 2ndQuadrant team.
It's slightly different from recommendations by draft RFC version (there's no counter), but fully within spec requirements. From practical point there's no difference at all.
I concur that Odyssey docs are insufficient to build a big picture. But I'm trying to answer every question in the Internets about Odyssey :)
Documenting is hard - everything seems obvious to me, but understand that may things are not that obvious.
// Odyssey maintainer
I think the book is free because Egor and PostgresPro want to develop the community. If you want to pay back - you can just start contributing to Postgres. No need to wait :)
reply