Re: [HACKERS] Patch: Write Amplification Reduction Method (WARM)

On Tue, Mar 21, 2017 at 6:56 AM, Amit Kapila <amit.kapila16@gmail.com> wrote:
>> Hmm, that test case isn't all that synthetic.  It's just a single
>> column bulk update, which isn't anything all that crazy, and 5-10%
>> isn't nothing.
>>
>> I'm kinda surprised it made that much difference, though.
>>
>
> I think it is because heap_getattr() is not that cheap.  We have
> noticed the similar problem during development of scan key push down
> work [1].

Yeah.  So what's the deal with this?  Is somebody working on figuring
out a different approach that would reduce this overhead?  Are we
going to defer WARM to v11?  Or is the intent to just ignore the 5-10%
slowdown on a single column update and commit everything anyway?  (A
strong -1 on that course of action from me.)

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
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