On 2020-Apr-06, Kyotaro Horiguchi wrote: > > * Andres complained that the "distance" column was not a great value to > > expose (20171106132050.6apzynxrqrzgh...@alap3.anarazel.de). That's > > right: it changes both by the insertion LSN as well as the slot's > > consumption. Maybe we can expose the earliest live LSN (start of the > > earliest segment?) as a new column. It'll be the same for all slots, > > I suppose, but we don't care, do we? > > I don't care as far as users can calculate the "remain" of individual > slots (that is, how far the current LSN can advance before the slot > loses data). But the "earliest live LSN (EL-LSN) is really not > relevant to the safeness of each slot. The distance from EL-LSN to > restart_lsn or the current LSN doesn't generally suggest the safeness > of individual slots. The only relevance would be if the distance from > EL-LSN to the current LSN is close to max_slot_wal_keep_size, the most > lagged slot could die in a short term.
Thanks for the revised version. Please note that you forgot to "git add" the test file, to it's not in the patch. I'm reviewing the patch now. -- Álvaro Herrera https://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
