May 2018
Intermediate to advanced
576 pages
30h 25m
English
Recovery continues until the end of the transaction log. WAL data is being written continually, so there is no defined end point; it is literally the last correct record. Each WAL record is individually CRC-checked so that we know whether a record is complete and valid before trying to process it. Each record contains a pointer to the previous record, so we can tell that the record forms a valid link in the chain of actions recorded in the WAL. As a result of that, recovery always ends with some kind of error in reading the next WAL record. That is normal and means the next record does not exist (yet).
Recovery performance can be very fast, though its speed does depend on the actions being recovered. The best way to test recovery ...