Обсуждение: Unlogged tables and BufferSync()

In BufferSync(), we have this:

>     /*
>      * Unless this is a shutdown checkpoint, we write only permanent, dirty
>      * buffers.  But at shutdown time, we write all dirty buffers.
>      */
>     if (!(flags & CHECKPOINT_IS_SHUTDOWN))
>         flags |= BM_PERMANENT;

That seems bogus to me. We're mixing CHECKPOINT_* flags and buffer BM_* 
flags in the same variable. Furthermore, we only use that flags variable 
to pass it down to CheckpointWriteDelay(), which only pays attention to 
CHECKPOINT_IMMEDIATE flag. The intention was probably to do "mask |= 
BM_PERMANENT" ?

--   Heikki Linnakangas  EnterpriseDB   http://www.enterprisedb.com

On Fri, Jan 6, 2012 at 7:52 AM, Heikki Linnakangas
<heikki.linnakangas@enterprisedb.com> wrote:
> In BufferSync(), we have this:
>
>>        /*
>>         * Unless this is a shutdown checkpoint, we write only permanent,
>> dirty
>>         * buffers.  But at shutdown time, we write all dirty buffers.
>>         */
>>        if (!(flags & CHECKPOINT_IS_SHUTDOWN))
>>                flags |= BM_PERMANENT;
>
>
> That seems bogus to me. We're mixing CHECKPOINT_* flags and buffer BM_*
> flags in the same variable. Furthermore, we only use that flags variable to
> pass it down to CheckpointWriteDelay(), which only pays attention to
> CHECKPOINT_IMMEDIATE flag. The intention was probably to do "mask |=
> BM_PERMANENT" ?

Ouch.  Yeah, that's a bug, will fix.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company