Heikki Linnakangas wrote:
>
> No, no crash is involved. Just a normal server shutdown and start:
>
> 1. Server shutdown is initiated
> 2. A shutdown checkpoint is recorded at XLOG point 1234, redo ptr is
> also 1234.
> 3. A XLOG_SWITCH record is written at 1235, right after the checkpoint
> record.
> 4. The last round of archiving is done. The partial WAL file
> containing the checkpoint and XLOG_SWITCH record is archived.
> 5. Postmaster exits.
>
> 6. Postmaster is started again. Since the system was shut down
> cleanly, no WAL recovery is done. The WAL insert pointer is
> initialized to right after the redo pointer, location 1235, which is
> also the location of the XLOG_SWITCH record.
> 7. The next WAL record written will be written at 1235, overwriting
> the XLOG_SWITCH record.
> 8. When the WAL file fills up, the system will try to archive the same
> WAL file again, this time with additional WAL records that after the
> checkpoint record.
So to get this down to a solution, it appears to be correct to execute
the RequestXLogSwitch right before CreateCheckPoint?
Regards,
Andreas
