> Could someone explain to this poor newbie (who is hoping to implement
> this) exactly what the issue is here? Like Tom, I could originally see
> no reason to worry about the LSN for file creation but I am very
> concerned that I have failed to grasp Tatsuo's concerns.
>
> Is there some reason why the relfilenode might change either during or
> as a result of recovery? Unless I have missed the point again, during
> recovery we must recreate files with exactly the same path, name and
> relfilenode as they would have originally been created, and in the same
> order relative to the creation of the relation. I see no scope for
> anything to be different.
Sorry for the confusion. I'm not very familiar with other DBMSs, and I
just don't know what kind of features for point in time recovery in
them could provide. One a scenario I could imagine is recovering
single table with different name. I'm not sure this is implemented by
other DBMS though.
BTW, next issue would be TRUCATE and CREATE/DROP DATABASE.
I regard this is not currently supported by WAL.
--
Tatsuo Ishii