How to remove an element from the array? about djorm-pgarray

[john-parton]

Array fields are cast to python lists. http://docs.python.org/2/tutorial/datastructures.html#more-on-lists
Should work, but haven't tested it: instance.array_prop.remove('some-element')
Remember to call instance.save()

[john-parton]

actually, you might need to do something more like this

arr = instance.array_prop
arr.remove('some-element')
instance.array_prop = arr
instance.save()

[ambasta]

The issue with the above approach is that editing large arrays becomes very expensive. Modifying an ArrayField with 500,000 elements takes over a second. I was wondering more on the lines if array_append/array_remove/array_replace(http://www.postgresql.org/docs/9.3/static/functions-array.html) etc were available instead.

[john-parton]

There's an array that has half a million records in your DB? I'd be curious to know what kind of application needs that kind of scale.

Anyways, I don't think there's anything like this "baked in."

You might take a look at django.db.models.compiler.SQLUpdateCompiler

[john-parton]

For now, you might just have to execute the SQL directly: https://docs.djangoproject.com/en/1.6/topics/db/sql/#executing-custom-sql-directly

[ambasta]

Figured as much, using raw sql atm.

As for the scale, there are dispatch numbers assigned to a coloader sitting in an arrayfield. Consumption of such a number across any of the few thousand coloading centers is a continous process, at which point it is promptly removed from the arrayfield.

Also thanks for the tip on django.db.models.compiler.SQLUpdateCompiler Will try to see if I can get a patch in.