We had a case recently where one of our DBs failed over to a new primary. To this server (old primary, and then new primary) we had connection from some kind of CDC tool (Debezium, I think).

The thing is that while there was failover, this tool read (using logical decoding) changes on old primary to location 1F1F/4ADC3348, and on new db, it connected from location 1F1F/4ADC4038. Which means that there was some WAL that was not decoded and sent to Debezium.

This is fixable, but we need to know what tables were touched in the WAL stream, that Debezium didn't see, if any. Perhaps we could also get ids/location of the rows that were there?

Continue reading What tables were touched within given range of wal LSN?