On 2020-May-13, Chapman Flack wrote: > Getting around to trying it out, simply changing the setting in > postgresql.conf before starting the server does not seem sufficient: > once it comes online, it has track_commit_timestamp on, but has not > populated the cache from transactions it applied during recovery.
Ah. I had not realized that that was what you wanted to do. > On the other hand, changing the setting in postgresql.conf *and* > poking a 1 in the track_commit_timestamp byte in pg_control, > and fudging the CRC accordingly, *then* starting the server, does > seem to do just as I had hoped. Nothing seems to complain or fall over, > and the transactions recovered from WAL now have timestamps visible > with pg_xact_commit_timestamp(). Nice hack. I guess you'd sooner have a supported way to enable the bit in pg_control. Is there a use case for this? -- Álvaro Herrera https://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
