Re: Acclerating INSERT/UPDATE using UPS

Christopher Browne wrote:
> kawasima@cs.tsukuba.ac.jp (Hideyuki Kawashima) wrote:
>> Joshua,
>>
>> I appreciate your quick & informative reply. And, I also really
>> appreciate your kind comments. Since I have joined this ML 3 hours
>> ago, I tried to be polite and slightly nervous. But I was relieved
>> by your message.
> 
> Your idea sounds interesting; there is likely to be a considerable
> resistance to mechanisms, however, that would be likely to make
> PostgreSQL less robust.
> 
> Be aware, also, that in a public forum like this, people are sometimes
> less gentle than Joshua.
> 
> The fundamental trouble with this mechanism is that a power outage can
> instantly turn a database into crud.

Correct, that is certainly a problem. However, I think the interesting
opportunity here is in devices that don't typically loose power. A PDA
for example.

The PostgreSQL footprint is actually quite small, and PDAs are getting
larger and larger in capacity. Heck, they even have 32GB SD now. In the
near future I believe we can expect to see always on, mini laptops as well.

From an deployable application perspective, this could be a big deal. We
are already starting to see very large traction in the Win32 desktop app
arena.


> 
> One may try to mitigate that problem by supporting the memory device
> with multiple power supplies *and* multiple UPSes.
> 
> But there is a not-inconsiderable risk that people will fail to read
> warnings, deploy databases in a way that leaves them exposed to total
> loss, and then lay blame at this community's feet.  I'm sure you can
> understand why the community might resist that...

I certainly can, but a feature left off by default and documented
thoroughly can mitigate a lot of that. Heck if we really wanted to we
could even make it a custom build; --with-lazy-wal ;)

Sincerely,

Joshua D. Drake



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