maria-developers team mailing list archive

[Sergey Vojtovich <svoj@xxxxxxxxxxx>]

Hi Sergei,

speaking of IANA time zone database, there seem to be no other long
abbreviations:
for i in `find /usr/share/zoneinfo -type f` ; do zdump $i; done|sed "s/.*2015 //"|while read line; do echo ${#line} $line; done|sort -n

But as we can see TZif permits abbreviations longer than 8 characters (while
MariaDB/MySQL doesn't). In theory if we just filter out such time zones, we
may miss very valid ones added in future (e.g. there're references to Mars
time which they hope will be added some day).

Also it is worth to note that there seem to be no other indication of what
is actually stored in abbreviation. I compared Factory and UTC and the only
difference was length of abbreviation and abbreviation text itself.

There're many solutions to this problem (in my preference order):
- filter out Factory time zone (1-st because simple)
- increase Abbreviation size in time_zone_transition_type (2-nd because
  this is incompatible change)
- filter out time zones with long abbreviations (suggested in MDEV-6236)
- filter out time zones with abbreviation == "Local time zone must be set..."
  (the MySQL way of fixing things) :)

So I'd prefer to error out and fix every individual occurence instead of
silently ignoring them. Please confirm you still don't like this proposed
solution.

Thanks,
Sergey

On Wed, Jun 03, 2015 at 03:58:55PM +0200, Sergei Golubchik wrote:
> Hi, Sergey!
> 
> On Jun 03, svoj@xxxxxxxxxxx wrote:
> > revision-id: 9bb9bde42dbf6f936faadeaa34cde838bf6b63dd
> > parent(s): 54977bee6705b9f3ebe2e534245defdb18ac31be
> > committer: Sergey Vojtovich
> > branch nick: mariadb
> > timestamp: 2015-06-03 14:30:09 +0400
> > message:
> > 
> > MDEV-6236 - [PATCH] mysql_tzinfo_to_sql may produce invalid SQL
> > 
> > Factory timezone is supposed "For companies who don't want to put time
> > zone specification in their installation procedures. When users run
> > date, they'll get the message. Also useful for the "comp.sources"
> > version."
> > 
> > This "message" is exposed as timezone abbreviation, which is supposed
> > to be short and thus may cause generated INSERT statements to fail.
> > 
> > Do not attempt to load Factory timezone.
> 
> Are you usure Factory is the only one with a message instead of a
> abbreviation?
> 
> Perhaps it'd be safer to filter out all timezones with extra-long
> "abbreviations"?
> 
> Regards,
> Sergei