Re: Fixing pgbench init overflow

Japin Li <japinli@hotmail.com>

From: Japin Li <japinli@hotmail.com>
To: Tatsuo Ishii <ishii@sraoss.co.jp>
Cc: johnhyvr@gmail.com, pgsql-hackers@postgresql.org, pgsql-hackers@lists.postgresql.org
Date: 2023-12-23T07:37:33Z
Lists: pgsql-hackers

Attachments

On Sat, 23 Dec 2023 at 15:22, Tatsuo Ishii <ishii@sraoss.co.jp> wrote:
>  <ME3P282MB316684190982F54BDBD4FE90B69BA@ME3P282MB3166.AUSP282.PROD.OUTLOOK.COM>
>
>>
>> On Sat, 23 Dec 2023 at 07:18, Chen Hao Hsu <johnhyvr@gmail.com> wrote:
>>> Hello,
>>>
>>> pgbench mixes int and int64 to initialize the tables.
>>> When a large enough scale factor is passed, initPopulateTable
>>> overflows leading to it never completing, ie.
>>>
>>> 2147400000 of 2200000000 tuples (97%) of
>>> pgbench_accounts done (elapsed 4038.83 s, remaining 98.93 s)
>>> -2147400000 of 2200000000 tuples (-97%) of
>>> pgbench_accounts done (elapsed 4038.97 s, remaining -8176.86 s)
>>>
>>>
>>> Attached is a patch that fixes this, pgbench -i -s 22000 works now.
>>
>> I think only the following line can fix this.
>>
>> +	int64			k;
>>
>> Do not need to modify the type of `n`, right?
>
> You are right. n represents the return value of pg_snprintf, which is
> the byte length of the formatted data, which is int, not int64.
>

Thanks for you confirmation! Please consider the v2 patch to review.

--
Regrads,
Japin Li
ChengDu WenWu Information Technology Co., Ltd.

Commits

  1. pgbench: Fix overflow in table populating when rows >= 2^31-1

  2. pgbench: Use COPY for client-side data generation