Re: making an unlogged table logged

On Wed, Jan 05, 2011 at 09:04:08AM -0500, Robert Haas wrote:
> On Tue, Jan 4, 2011 at 10:56 PM, Rob Wultsch <wultsch(at)gmail(dot)com> wrote:
> > 1. Could the making a table logged be a non-exclusive lock if the
> > ALTER is allowed to take a full checkpoint?
>
> No, that doesn't solve either of the two problems I described,
> unfortunately.
>
> > 2. Unlogged to logged has giant use case.
>
> Agree.
>
> > 3. In MySQL I have had to ALTER tables to engine BLACKHOLE because
> > they held data that was not vital, but the server was out of IO.
> > Going logged -> unlogged has a significant placed, I think.
>
> Interesting. So you'd change a logged table into an unlogged table
> to cut down on I/O, and take the risk of losing the data if the
> server went down?

BLACKHOLE is a "storage engine" that's equivalent to /dev/null, so it
wasn't a risk /per se/.

Cheers,
David.
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