maria-developers team mailing list archive

[Alexander Barkov <bar@xxxxxxxxxxx>]

Hi Sergei,

I tested comparison behaviour for various different situations.

Please find the comment with the summary table in the end of:
https://mariadb.atlassian.net/browse/MDEV-7649


Currently there are 5 possible reactions on bad bytes on comparison,
depending on the collation, presence of an index, and 
character_set_connection value:

- truncate on bad byte, compare only the well-formed prefix (#1)
- treat bad bytes as '?' (#7 and #8)
- empty set with no warning (#3)
- empty set with a warning (#2)
- error (#5 and #6)


I'm in doubts what to dofor 10.1 and for 5.5. Please suggest.


1. For 10.1 or 10.2 I think it would be nice to make all these cases
work  exactly the same way. I am not sure which way would be the best.
Any ideas?



2. For 5.5 we need to fix the bug with minimal changes. Do you agree?
I suggest we fix only #1 and maybe #2.

How we fix 5.5 now should probably depend on how we'll fix 10.1,
to avoid changing behaviour many times. Please suggest.


Thanks.