Rainer Gerhards <rgerha...@gmail.com> was heard to say: > That's what I would expect. However, I think it would be useful to > have a call like "drvrTXSupport()" returning 1 if the driver supports > transaction and 0 otherwise. That way, an app could either fall back > to non-transcation mode OR tell the user that the database system is > not suitable for that kind of application. That would probably also > provide a smooth migration path, were only the primary TX interface > needs to be implemented and drivers can be upgraded as time permits > (assuming that some drivers are maintained by external entities).
In fact, we already have a (not well documented) infrastructure for things like this in place. Every driver keeps a list of boolean "capabilities" which is merely a key-value list of whatever we think is useful or necessary. To date, only the "safe_dlclose" capability seems to be used, see e.g. dbd_initialize in libdbi-drivers/drivers/mysql/dbd_mysql.c. There is an internal function _dbd_register_driver_cap() which can be used by the drivers to announce a capability. And there is a public function dbi_driver_cap_get() which allows applications to query the list of capabilities at runtime. So all we'd have to do is modify the drivers and have them add a "transaction_support" capability set to 1 for those who support transactions. > > For TX support, I'd expect calls for > > - begin transaction > - commit > - rollback > > that's it, so all in all 4 calls. Would you agree to that? yes, except that we don't need the drvrTXSupport() function as we can use dbi_driver_cap_get() instead. > >> This should be easy to retrofit. I'lls see if I find >> some time but feel free to beat me at it. > > I am quite busy myself at the moment, but I could try and see if I > could craft something along that path... > > Rainer regards, Markus -- Markus Hoenicka http://www.mhoenicka.de AQ score 38 ------------------------------------------------------------------------------ Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov _______________________________________________ libdbi-users mailing list libdbi-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libdbi-users
