Re: Let's drop two obsolete features which are bear-traps for novices

Josh,

Do you have a list of what needs to be done to keep the MONEY type?
What is wrong with it?

Thanks,
-cktan

On Mon, Nov 3, 2014 at 10:30 PM, Feng Tian <ftian(at)vitessedata(dot)com> wrote:
> Hi,
>
> This is Feng from Vitesse. Performance different between Money and Numeric
> is *HUGE*. For TPCH Q1, the performance difference is 5x for stock
> postgres, and ~20x for vitesse.
>
> Stock postgres, for my laptop, TPCH 1G, Q1, use money type ~ 9s, use Numeric
> (15, 2) is ~53s.
>
> Kevin,
> test=# do $$ begin perform sum('10000.01'::numeric) from
> generate_series(1,10000000); end; $$;
>
> This may not reflect the difference of the two data type. One aggregate is
> not where most of the time is spent. TPCH Q1 has many more computing.
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> On Mon, Nov 3, 2014 at 4:54 AM, Michael Banck <michael(dot)banck(at)credativ(dot)de>
> wrote:
>>
>> Am Sonntag, den 02.11.2014, 12:41 -0500 schrieb Tom Lane:
>> > BTW, after reflecting a bit more I'm less than convinced that this
>> > datatype is completely useless. Even if you prefer to store currency
>> > values in numeric columns, casting to or from money provides a way to
>> > accept or emit values in whatever monetary format the LC_MONETARY locale
>> > setting specifies. That seems like a useful feature, and it's one you
>> > could not easily duplicate using to_char/to_number (not to mention that
>> > those functions aren't without major shortcomings of their own).
>>
>> As an additional datapoint, Vitesse Data changed the DB schema from
>> NUMERIC to MONEY for their TPCH benchmark for performance reasons: "The
>> modification to data types is easy to understand -- money and double
>> types are faster than Numeric (and no one on this planet has a bank
>> account that overflows the money type, not any time soon)."[1] And
>> "Replaced NUMERIC fields representing currency with MONEY"[2].
>>
>> Not sure whether they modified/optimized PostgreSQL with respect to the
>> MONEY data type and/or how much performance that gained, so CCing CK Tan
>> as well.
>>
>>
>> Michael
>>
>> [1]
>> http://vitesse-timing-on.blogspot.de/2014/10/running-tpch-on-postgresql-part-1.html
>> [2] http://vitessedata.com/benchmark/
>>
>> --
>> Michael Banck
>> Projektleiter / Berater
>> Tel.: +49 (2161) 4643-171
>> Fax: +49 (2161) 4643-100
>> Email: michael(dot)banck(at)credativ(dot)de
>>
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>
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