Table and colums with more then 30 chars can no longer be found / queried after migrating from django 3.2 to 4.0 using an Oracle backend

[Paul in 't Hout]

While in the proces of updating our project from Django 2.2 to 3.2 to 4.0 I noticed that things started to break down in 4.0.

Since upgrading to 4.0, tables with names longer than 30 chars fail with
ORA-00942: table or view does not exist
models with columns with names longer than 30 chars fail with
ORA-00904: "COMPONENT_ATTRIBUTE_METADATA"."REQUIRES_ILOM_CONNECT_FOR_DD63": invalid identifier

When I run the following on django 2.2 / 3.2.13 with python 3.6

from django.db.backends.utils import truncate_name
truncate_name("very_long_database_table_or_column" length=30)
Out[7]: 'VERY_LONG_DATABASE_TABLE_O20cb'

Then run the same on django 4.0.5 with python 3.9

from django.db.backends.utils import truncate_name
truncate_name("very_long_database_table_or_column", length=30)
Out[6]: 'very_long_database_table_o0c9a'

The hash value is different. As a result a table or column name is queried that does not exist, because they where created using the older algorithm.

I believe this was broken by this change: https://code.djangoproject.com/ticket/32653