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
28197	PostgreSQL introspection's get_constraints() retrieves index fields in arbitrary order	Mactory	nobody	"When trying to run the migrations from scratch for the django-blog-zinna app the first time, the migration command threw the following error when run under django 1.11 on a postgresql db:
`ValueError: Found wrong number (0) of constraints for zinnia_entry(slug, creation_date)`

After digging through the code, I found out, that the `array_agg` function used in the query at `db.backends.postgresql.introspection` line 196 aggregates the values in an arbitrary order."	Bug	closed	Database layer (models, ORM)	1.11	Release blocker	fixed			Accepted	1	0	0	0	0	0