Would be possible to check the integrity between two database servers?
Both servers are slaves (streaming replication + wal_files) but I believe one of them, when recovered from wal_files in a fast outage we got, got recovered not 100%.
Did you mean to say recovery is not successful or complete ? How did you know that recovery is not 100% ? Any errors, messages etc ?
How could I check the data between both DB?
That is something which Application needs to do. From database perspective you can check if the databases are in complete sync.
