Re: proposal: CREATE DATABASE vs. (partial) CHECKPOINT

On Mon, Oct 27, 2014 at 4:44 PM, Heikki Linnakangas <hlinnakangas(at)vmware(dot)com
> wrote:

> On 10/27/2014 01:06 PM, Atri Sharma wrote:
>
>>
>>>
>>>
>>>> To solve #1, we could redesign CREATE DATABASE so that replaying the
>>> DBASE_CREATE record doesn't zap the old directory, and also doesn't copy
>>> any files. We could instead just assume that if the transaction commits,
>>> all the files have been copied and fsync'd already, like we assume that
>>> if
>>> a CREATE INDEX commits in wal_level=minimal, the underlying file was
>>> fsync'd before the commit.
>>>
>>>
>> Do you mean that during a recovery, we just let the database directory be
>> and assume that it is in good shape since the transaction committed
>> originally?
>>
>
> Right.

It does make sense, however, with the checkpoint after creating the files
gone, the window between the creation of files and actual commit might be
increased, increasing the possibility of a crash during that period and
causing an orphan database. However, my understanding of the consequences
of removing the checkpoint might be incorrect, so my fears might be wrong.

Regards,

Atri