Re: SELECT .. FOR UPDATE: find out who locked a row

Greetings,

Please don't top-post.

* Melvin Davidson (melvin6925(at)gmail(dot)com) wrote:
> this whole discussion started because Enrico did not originally specify the
> PostgreSQL version he was working with. So after he did advise it was for
> 9.6, I felt it necessary to explain to him why a certain section of my
> query was commented out and that it would also work for 10. I have
> previously made it a policy to request ops include the PostgreSQL version
> and O/S when submitting to this list, but I was berated by others for
> always requesting ops to provide that extremely difficult information to
> obtain.

There's a difference between saying that a particular query is intended
for certain versions and to ask for what version while providing useful
information, and just immediately replying to every email which doesn't
specify it asking for what the version and OS is. The former is being
helpful and specific while soliciting for additional information, while
the latter tends to just create noise on the list, particularly when the
question isn't ultimately relevant.

Note that the above comments are entirely generic- I'm not aware of the
specific emails which you're referring to or why it was suggested that
they weren't helpful. Specific concerns regarding list usage should
really be addressed to the list moderators and not individuals taking
action on their own.

> I also felt it important that I express my opinion that the changes needed
> were caused by what I felt was cosmetic and unnecessary changes to the
> catalog. There is an old saying "If it ain't broke, don't fix it" and that
> certainly applies here.

There was a great deal of discussion and consideration for the changes
and specific reasons why they were made.

> Now, as to your request for me to read the thread in the url's you
> suggested, I did read most of the content. I note that the entire
> discussion was amongst
> PostgreSQL-development <pgsql-hackers(at)postgreSQL(dot)org>, So at no time
> was the generic population of PostgreSQL users and DBA's involved.

That version of PostgreSQL, as with all of them, went through a beta
period where we specifically ask for feedback from users. Serious
concerns raised during that time period do result in changes being made
prior to release.

> Therefore, said population, myself included, had no foreknowledge of the
> intended changes which is the cause of the problem. Therefore your
> statement "you might want to consider speaking up in some reasonable time
> frame, not six years later" is abrasive at best, since I, and others, only
> found out about it after the fact. Not to mention, even if I did complain
> earlier, I seriously doubt the changes could or would be reversed.

If you're interested in having a say in what will be included in the
next version of PostgreSQL then I strongly encourage you, and all users,
to work with the beta packages that are put out, every year, for people
to test with.

> At this point I have said all I have to say and will discuss it no further.
> I can only strongly recommend that in the future, proposed changes to
> system catalogs that could adversely affect existing scripts and
> applications be sent to the generic PostgreSQL population (IE:
> pgsql-general(at)lists(dot)postgresql(dot)org) for comment BEFORE said changes are
> implemented.

Beta releases are announced through the pgsql-announce mailing list,
which is a list that has a great deal less traffic than -general and one
which I'd suggest all users subscribe to, to be aware of changes which
are likely to be in the next release and to test to see if there are any
serious issues, and also to update their applications and queries in
advance of changes being released.

Thanks!

Stephen