Re: Fix GetOldestXmin comment

From: Masahiko Sawada <sawada(dot)mshk(at)gmail(dot)com>
To: Amit Kapila <amit(dot)kapila16(at)gmail(dot)com>
Cc: PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: Fix GetOldestXmin comment
Date: 2017-05-30 17:43:22
Message-ID: CAD21AoDM9FQ7n_b9HTSjFMhJKhsWdS2sp61T1nov7CnqEZZfSw@mail.gmail.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

On Tue, May 30, 2017 at 11:07 PM, Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
> On Tue, May 30, 2017 at 6:32 AM, Masahiko Sawada <sawada(dot)mshk(at)gmail(dot)com> wrote:
>> Hi,
>>
>> While reading source code, I realized that comment of GetOldestXmin mentions;
>>
>> * if rel = NULL and there are no transactions running in the current
>> * database, GetOldestXmin() returns latestCompletedXid.
>>
>> However, in that case if I understand correctly GetOldestXmin()
>> actually returns latestCompletedXid + 1 as follows;
>>
>
> Isn't there another gotcha in above part of the comment, shouldn't it
> say rel != NULL? AFAICS, when rel is NULL, it considers all databases
> not only current database.
>

Hmm it could return latestCompletedXid in that case. I think I
understood now, Thank you!

Regards,

--
Masahiko Sawada
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center

In response to

Browse pgsql-hackers by date

  From Date Subject
Next Message Peter Eisentraut 2017-05-30 17:55:04 Re: Replication status in logical replication
Previous Message Masahiko Sawada 2017-05-30 17:25:06 Re: Re: Alter subscription..SET - NOTICE message is coming for table which is already removed