On 17 August 2017 at 07:30, Michael Paquier <michael.paqu...@gmail.com> wrote:
> > Definitely agreed on that. Any move function would need to check if > the WAL position given by caller is already newer than what's > available in the local pg_wal (minimum of all other slots), with a > shared lock that would need to be taken by xlog.c when recycling past > segments. A forward function works on a single entry, which should be > disabled at the moment of the update. It looks dangerous to me to do > such an operation if there is a consumer of a slot currently on it. > > pg_advance_replication_slot(...) ERROR's on logical slot, for now. Physical slots only. Forward-only. Future work to allow it to use the logical decoding infrastructure to fast-forward a slot by reading only catalog change information and invalidations, either via a dummy output plugin that filters out all xacts, or by lower level use of the decoding code. Reasonable? -- Craig Ringer http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services
