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Re: 9243921c84b: Make all #sql temporary table names uniform




> > ALTER PARTITION shadow files:
> > #sql-shadow-'original_table_name'
> Please, add a thread_id here at the end. normally MDL should ensure that
> no two threads can have a shadow for the same table at the same time,
> but we have enough bugs as it is to introduce another vector when two
> threads can overwrite each other temp files.

That would make the file name even longer and I am not sure what
happens if we table names goes much over
 NAME_LEN.  I don't have time just now to check for possible name
overruns (I think it should be save as most
engines are using FN_REFLEN, but better safe than sorry.

> > Names from the temp pool:
> > #sql-name-current_pid-pool_number
> Would you mind if I drop temp pool completely in 10.5?
> It was added by Jeremy in January 2001 with the comment
>   Added --temp-pool option to mysqld.  This will cause temporary files
>   created to use a small set of filenames, to try and avoid problems
>   in the Linux kernel.
> And I doubt it's still an issue in 2020.

I think that reusing file names is still something that is a problem.
We should do some tests for that before skipping this code.
It's not a lot a code after all.


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