Phase 1:
Is the DBPAGES phase. It Scans and dumps all allocated
pages, data and log, without checking for any changes made
while the phase is going on. (The first phase writes all the
used pages, and keeps lists of pages that were modified in
order to transmit those to backup server.)
Phase 2:
Is the FLUSHPAGES phase. All the data pages that were
modified but not logged during
phase 1. The dump instant is the end of this phase, i.e.
recovery restores to this point after this phase. (The
second phase takes that list of modified pages and writes
them to the dump.)
Phase 3:
Is the SCANLOGPAGES phase. Log pages are dumped again for
up-to-the-minute changes. (The third phase is a list of log
pages that changed while the second phase was going on.)
Dump transaction only uses Phase 3.
In this way, we ensure that the dump contains the complete
set of pages, and log records modifying those pages, that
occurred up to and including the "dump instant". The dump
instant is the point upto which the load will recover .
transactions completing before the dump instant will be
recovered, those not yet completed will rolled back.
HTH,
Vivek
Post by unknownCan anyone explain the 3 dump phases in detail??