I'd like to propose generic functions (probably in an extension, or in core if not possible otherwise) to facilitate streaming existing data from the database *in the same format* that one would get if these would be the changes decoded by a logical decoding plugin.
The idea is to use a snapshot returned from CREATE_REPLICATION_SLOT command of the replication protocol to get a consistent snapshot of the database, then start listening to new changes on the slot.
It sounds like this is already possible.
--
Simon Riggs http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
