On 2020-Jun-22, movead...@highgo.ca wrote: > hello hackers, > > When I try to use pg_resetwal tool to skip some transaction ID, I get a > problem that is > the tool can accept all transaction id I offered with '-x' option, however, > the database > may failed to restart because of can not read file under $PGDATA/pg_xact. For > example, the 'NextXID' in a database is 1000, if you offer '-x 32769' then > the database > failed to restart.
Yeah, the normal workaround is to create the necessary file manually in order to let the system start after such an operation; they are sometimes necessary to enable testing weird cases with wraparound and such. So a total rejection to work for these cases would be unhelpful precisely for the scenario that those switches were intended to serve. Maybe a better answer is to have a new switch in postmaster that creates any needed files (incl. producing associated WAL etc); so you'd run pg_resetwal -x some-value postmaster --create-special-stuff then start your server and off you go. Now maybe this is too much complication for a mechanism that really isn't for general consumption anyway. I mean, if you're using pg_resetwal, you're already playing with fire. -- Álvaro Herrera https://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
