Querying after partitioning returns an empty result

[tahmidkhan]

The project is running on Django. I set up my model as follows:

import architect
from django.contrib.postgres.fields import JSONField

@architect.install('partition', type='range', subtype='string_firstchars', constraint='10', column='collection')
class PartitionedDocument(models.Model):
	collection = models.CharField(max_length=10)
	content = JSONField(default=dict)

In other words, I am partitioning using the first 10 characters of the collection field. Plus, I ensure the collection is always a string of 10 characters (from a pre-determined list), so its a nice partitioning system. The list looks like this:

collection_labels = [
	'91IJAYXLPc',
	'kzMZFCHavP',
	'SMyJzyY9ze',
	'EAW95zQtED',
	'AzDWtgZ6MA',
	'Kv7wrKX9m3',
	'BO9CsGIqpd',
	'fQhDlqVNJs',
	'tvj1zF3Nmm',
	'IAPzdfsjFM',
	'hLuumRvCK4',
	'ErwIeGjMwE',
	'ebS3sy7xmJ',
	'aLyd8Hrcpe',
	'8hdhGCFmJU',
	'AfT7kLR0ep',
	'0MPS0KLsrT',
	'k17vDmktNB',
	'SluHmP1X2K',
	'9OMXJZJqHE'
]

Anyway, I added some data to my database after doing all this, and then ran a query like so:

PartitionedDocument.objects.annotate(
    full_name = RawSQL("(content->>'full_name')::text", []),
    age = RawSQL("(content->>'age')::int", [])
).filter(
    age__gte = 30
).extra(where=["lower(substr(collection, 1, 10)) = '91IJAYXLPc'"])

If everything went correctly, I should only be hitting the table that corresponds to the collection with a value of '91IJAYXLPc', and then I would filter based on the JSONField. I know for a fact that objects that fall under this condition exists in my database, however, the queryset returned is empty.

Did I do something wrong? Thanks.