Re: [PATCH] Rename pg_switch_xlog to pg_switch_wal

On Mon, Feb 6, 2017 at 1:24 PM, Michael Paquier
<michael(dot)paquier(at)gmail(dot)com> wrote:
> On Sat, Feb 4, 2017 at 6:39 AM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
>> On Fri, Feb 3, 2017 at 5:21 AM, Stephen Frost <sfrost(at)snowman(dot)net> wrote:
>>> Daniel,
>>>
>>> * Daniel Verite (daniel(at)manitou-mail(dot)org) wrote:
>>>> What if we look at the change from the pessimistic angle?
>>>> An example of confusion that the change would create:
>>>> a lot of users currently choose pg_wal for the destination
>>>> directory of their archive command. Less-informed users
>>>> that set up archiving and/or log shipping in PG10 based on
>>>> advice online from previous versions will be fairly
>>>> confused about the missing pg_xlog, and the fact that the
>>>> pg_wal directory they're supposed to create already exists.
>>>
>>> One would hope that they would realize that's not going to work
>>> when they set up PG10. If they aren't paying attention sufficient
>>> to realize that then it seems entirely likely that they would feel
>>> equally safe removing the contents of a directory named 'pg_xlog'.
>>
>> So... somebody want to tally up the votes here?
>
> Here is what I have, 6 votes clearly stated:
> 1. Rename nothing: Daniel,
> 2. Rename directory only: Andres
> 3. Rename everything: Stephen, Vladimir, David S, Michael P (with
> aliases for functions, I could live without at this point...)

I vote for 1.
I still wonder how much the renaming of pg_xlog actually helps very careless
people who remove pg_xlog becase its name includes "log". I'm afraid that
they would make another serious mistake (e.g., remove pg_wal because it has
many files and it occupies large amount of disk space) even after renaming
to pg_wal. The crazy idea, making initdb create the empty file with the name
"DONT_REMOVE_pg_xlog_IF_YOU_DONT_WANT_TO_LOSE_YOUR_IMPORTANT_DATA"
in $PGDATA seems more helpful. Anyway I'm afraid that the renaming would
cause more pain than gain.

Regards,

--
Fujii Masao