If MySQL client was not compiled with the --enable-thread-safe-client flag, then the database provider will only allow connections to be opened from the thread which initializes Libgda. Otherwise there is no limitation.

Timezone information associated with time and timestamp data types is not stored by MySQL, so when executing statements all the variables containing a time or timestamp information are converted to GMT (timezone 0) before the execution happens. The consequence is that for example if a variable holds the "11:23:55+2" time (11 hours, 23 minutes and 55 seconds, at GMT + 2), then the actual time stored in the database will be "09:23:55", the same time but GMT.