RE: Global shared meta cache - Mailing list pgsql-hackers

From Ideriha, Takeshi
Subject RE: Global shared meta cache
Date
Msg-id 4E72940DA2BF16479384A86D54D0988A6F131C7E@G01JPEXMBKW04
Whole thread Raw
In response to Re: Global shared meta cache  (AJG <ayden@gera.co.nz>)
List pgsql-hackers
>-----Original Message-----
>From: AJG [mailto:ayden@gera.co.nz]
>Sent: Wednesday, June 27, 2018 3:21 AM
>To: pgsql-hackers@postgresql.org
>Subject: Re: Global shared meta cache
>
>Ideriha, Takeshi wrote
>> 2) benchmarked 3 times for each conditions and got the average result
>> of TPS.
>>                                      |master branch | prototype      |
>> proto/master (%)
>>
>> ------------------------------------------------------------------------------------
>>    pgbench -c48 -T60 -Msimple -S   | 131297       |130541       |101%
>>    pgbench -c48 -T60 -Msimple      | 4956          |4965       |95%
>>    pgbench -c48 -T60 -Mprepared -S |129688       |132538       |97%
>>    pgbench -c48 -T60 -Mprepared    |5113       |4615       |84%
>>
>>
>> 001_global_meta_cache.patch (6K)
>> <http://www.postgresql-archive.org/attachment/6026686/0/001_global_
>> meta_cache.patch>
>
>
>Hello,
>Apologies for question. I thought I would just double check percentages that have
>been presented.
>Is the percentage calculation correct?
>as #1 and #3 look inverted to me (say lower when should be higher and vice versa),
>and
>#2 and #4 look incorrect generally (percentages look much larger than they should be
>based on numbers.
>
>I.e. Msimple -S the protype had slightly worse tps performance (130541) versus
>Master (131297). I would expect the percentage to be e.g. 99% not 101%
>
>But I may be misunderstanding something :)
>
>Also, Msimple is 4956 master versus 4965 prototype. Just 9 tps change. A very slight
>improvement in tps. but the percentage provided is 95%. I would expect it to be just
>over 100%?
>Again, maybe im not understanding, and hoping it is just my error :)
>
>
>
>--
>Sent from: http://www.postgresql-archive.org/PostgreSQL-hackers-f1928748.html
>
Hi, 
Thank you for comments and sorry for late replay.
Thanks to you, I noticed I made a mistake.
As you pointed out, I think my calculation is wrong.

I also need to change some settings of postgresql.conf and pgbench. 
So I'm going to measure performance again and submit the result.

Regards,
Takeshi Ideriha



pgsql-hackers by date:

Previous
From: Amit Langote
Date:
Subject: documentation about explicit locking
Next
From: Peter Eisentraut
Date:
Subject: Re: Failed assertion due to procedure created with SECURITY DEFINERoption