Verify if django-ingester is respecting kcidb limitations on fields update

[nuclearcat]

In old kcidb ingestion we had certain limitations imposed, such as to not change checkout/build/test fields after they are set (we cannot update/delete non-null values).

Location(approx): kcidb/db/sql/schema.py:264-286
The INSERT statement uses ON CONFLICT ... DO UPDATE SET with COALESCE functions to preserve existing values:

ON CONFLICT (primary_key_columns) DO UPDATE SET
column_name = COALESCE(table.column_name, excluded.column_name)

The logic works as follows:

1. Lines 264-269: Identifies primary key columns for the conflict resolution
2. Lines 270-286: For non-primary-key columns, it uses COALESCE to decide which value to keep:
   - If prio_db is True: COALESCE(table.column, excluded.column) - keeps existing DB values if not NULL
   - If prio_db is False: COALESCE(excluded.column, table.column) - prefers new values if not NULL
   - For columns with conflict_func (like timestamps): Uses a specific function (e.g., GREATEST) to resolve conflicts
   (still need to check where and how prio_db used)

[MarceloRobert]

@nuclearcat I have a question, can that limitation apply to just a couple of specified tables?
I'm saying that because in our effort of denormalizing views, we will create new tables in the database, and those tables will require update/delete

[nuclearcat]

As i know it is not, but we might reverse this limitation. I am not sure we should impose artificial limitations on labs, the only exception - we need to make sure some submissions wont delete useful data by mistake.

[MarceloRobert]

Ok, so some testing is still needed then. We'll work on it when possible