I should probably be more specific. Without using savepoints nested transaction functionality couldn't be achieved with MySQL (and only with InnoDB). START TRANSACTION does an implicit commit so the previous transaction is not subsumed.
I suppose that savepoint based functionality could be implemented for MySQL in lieu of nested transactions though. See: http://dev.mysql.com/doc/refman/5.0/en/implicit-commit.html 2010/5/18 Ian Lewis <ianmle...@gmail.com>: > Am I missing something? Are we talking about doing some kind of > transaction management at the application level? If not then it's > worth noting that in MySQL you cannot begin a transaction twice > without commiting or rolling back. i.e. nested transactions are not > supported. > > On Tue, May 18, 2010 at 1:05 AM, Piet Delport <pjdelp...@gmail.com> wrote: >> 2010/5/17 Ian Lewis <ianmle...@gmail.com>: >>> >>> I suppose that it's worth mentioning that any support for nested >>> transactions will not be portable to different databases (particularly >>> MySQL) and probably would need to be documented accordingly. >> >> How do you mean? >> >> Django-level transaction block nesting is portable to any database that >> supports transactions: The top-level transaction subsumes nested >> transactional blocks. >> >> If you are referring to SQL savepoints, supporting them is entirely >> optional: nested transaction blocks do not depend on it in any way. >> Savepoints are more like an optional performance optimization than >> anything else, and just give applications the option of doing >> finer-grained failure recovery in certain cases without changing the >> meaning of transactional blocks. (The proposal above only mentions >> savepoints for completeness, and because support for them would be >> natural to integrate.) >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Django developers" group. >> To post to this group, send email to django-develop...@googlegroups.com. >> To unsubscribe from this group, send email to >> django-developers+unsubscr...@googlegroups.com. >> For more options, visit this group at >> http://groups.google.com/group/django-developers?hl=en. >> >> > > > > -- > ======================================= > 株式会社ビープラウド イアン・ルイス > 〒150-0021 > 東京都渋谷区恵比寿西2-3-2 NSビル6階 > email: ianmle...@beproud.jp > TEL:03-6416-9836 > FAX:03-6416-9837 > http://www.beproud.jp/ > ======================================= > -- ======================================= 株式会社ビープラウド イアン・ルイス 〒150-0021 東京都渋谷区恵比寿西2-3-2 NSビル6階 email: ianmle...@beproud.jp TEL:03-6416-9836 FAX:03-6416-9837 http://www.beproud.jp/ ======================================= -- You received this message because you are subscribed to the Google Groups "Django developers" group. To post to this group, send email to django-develop...@googlegroups.com. To unsubscribe from this group, send email to django-developers+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/django-developers?hl=en.
