回复: Add 64-bit XIDs into PostgreSQL 15

[adherent postgres]

Hi Pavel Borisov
Now the disk performance has been improved many times, and the capacity has 
also been increased many times,The wal log already supports lz4 and zstd 
compression, I think each XLOG record size will increase at least by 4 bytes 
which is not a big problem.What about your opinion?

Best whish



发件人: Pavel Borisov 
发送时间: 2022年12月9日 22:13
收件人: adherent postgres 
抄送: Aleksander Alekseev ; 
pgsql-hackers@lists.postgresql.org ; Chris 
Travers ; Chris Travers ; Bruce 
Momjian 
主题: Re: Add 64-bit XIDs into PostgreSQL 15

Hi, Adherent!

On Fri, 9 Dec 2022 at 17:54, adherent postgres
 wrote:
>
> Hi Aleksander Alekseev
>  I think the xids 32bit transformation project has been dragged on for too 
> long. Huawei's openGauss referenced this patch to implement xids 64bit, and 
> Postgrespro also implemented xids 64bit, which is enough to prove that their 
> worries are redundant.I think postgresql has no reason not to implement xid 
> 64 bit. What about your opinion?

I agree it's high time to commit 64xids into PostgreSQL.

If you can do your review of the whole proposed patchset or only the
part that is likely to be committed earlier [1] it would help a lot!
I'd recommend beginning with the last version of the patch in thread
[1]. First, it is easier. Also, this review is going to be useful
sooner and will help a committer on January commitfest a lot.
[1]: 
https://www.postgresql.org/message-id/CAFiTN-uudj2PY8GsUzFtLYFpBoq_rKegW3On_8ZHdxB1mVv3-A%40mail.gmail.com

Regards,
Pavel Borisov,
Supabase

回复: Add 64-bit XIDs into PostgreSQL 15

[adherent postgres]

Hi Chris Travers
 Robertmhaas said that the project Zheap is 
dead（https://twitter.com/andy_pavlo/status/1590703943176589312）, which means 
that we cannot use Zheap to deal with the issue of xid wraparound and dead 
tuples in tables. The dead tuple issue is not a big deal because I can still 
use pg_repack to handle, although pg_repack will cause wal log to increase 
dramatically and may take one or two days to handle a large table. During this 
time the database can be accessed by external users, but the xid wraparound 
will cause PostgreSQL to be down, which is a disaster for DBAs. Maybe you are 
not a DBA, or your are from a small country, Database system tps is very low, 
so xid32 is  enough for your database system ,  Oracle's scn was also 32bits, 
however, Oracle realized the issue and changed scn to 64 bits. The transaction 
id in mysql is 48 bits. MySQL didn't fix the transaction id wraparound problem 
because they think that 48 bits is enough for the transaction id. This project 
has been running for almost 1 year and now it is coming to an end. I strongly 
disagree with your idea of stopping this patch, and I suspect you are a 
saboteur. I strongly disagree with your viewpoint, as it is not a fundamental 
way to solve the xid wraparound problem. The PostgreSQL community urgently 
needs developers who solve problems like this, not bury one' head in the sand


Best whish


发件人: Peter Geoghegan 
发送时间: 2022年12月1日 0:35
收件人: Robert Haas 
抄送: Chris Travers ; Bruce Momjian ; 
Aleksander Alekseev ; 
pgsql-hackers@lists.postgresql.org ; Chris 
Travers ; Fedor Sigaev ; Alexander 
Korotkov ; Konstantin Knizhnik ; 
Nikita Glukhov ; Yura Sokolov 
; Maxim Orlov ; Pavel Borisov 
; Simon Riggs 
主题: Re: Add 64-bit XIDs into PostgreSQL 15

On Wed, Nov 30, 2022 at 8:13 AM Robert Haas  wrote:
> I haven't checked the patches to see whether they look correct, and
> I'm concerned in particular about upgrade scenarios. But if there's a
> way we can get that part committed, I think it would be a clear win.

+1

--
Peter Geoghegan