Re: equivalent thing of mtr in mysql

On 7/12/22 12:57, Peter J. Holzer wrote:
> On 2022-07-12 22:39:31 +0800, merryok wrote:
>> Hi, guys. I'm new here.
>>
>> I'm eager to figure out what is the equivalent thing of mtr in mysql in PG.
> What is MTR? A search for "mtr mysql" yields "mysql test run" and
> "multi-threaded replication", neither of which seems to be what you are
> talking about. When referring to concepts from other databases, please
> include a link to the relevant documentation.
>
>> When a dml operation occurs, it may modify multiple pages and gererate multiple
>> redo log records. mtr can make those logs atomically be transferred to log
>> buffer and written to disk.
>> I think same situation exists in PG, but I can't find something like mtr, why ?

I thought OP was hinting at WAL stuff defn here
<https://www.postgresql.org/docs/current/wal-intro.html>
> Transactions in PostgreSQL are always atomic (That should also be the
> case with MySQL, unless you use MyISAM tables). Ensuring that these
> changes also result in an atomic disk write seems to be both pointless
> and impossible (that might be many gigabytes of data).
>
> hp
>