id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
24794	"RunPython parameter ""atomic"" is ineffective."	Vernon Cole	nobody	"This report is similar to #24630, but differs from it in detail. The fix for #24630 is insufficient for this scenario.

I am attempting to apply a data migration to a Postgres table with millions of records -- my first attempt (using RunSQL) failed and rolled back after about two days of run time.  It appears that the job must be done in smaller chunks, so I rewrote the migration using RunPython, limiting the size of the result set with a slicing, with set_autocommit(False) and explicit commit calls.  

It appears from the documentation that the built-in transaction control can be overridden:
[https://docs.djangoproject.com/en/1.8/topics/db/transactions/] 

  This should be safe, but may cause a crash if you attempt to use the schema_editor provided on these backends; in this case, please set atomic=False.

But ""atomic=False"" has no effect on the operation of the migration. Stepping through the code using a debugger, I failed to find anyplace where that parameter is actually used, nor could I find a way to short-cut the atomic transaction.  It appears that I will need to write a stand-alone program to migrate the data. 

Unless someone more talented than me can find a way to make ""atomic=False"" actually work, it should be removed from the code and from all documentation; or the documentation made more explicit to explain when and where it does work.
"	Bug	closed	Migrations	1.8	Normal	duplicate	RunPython atomic commit		Unreviewed	0	0	0	0	0	0