Closes #21016: Add missing MPTT tree indexes #354

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MrUnknownDE · 2026-04-05T16:27:05+02:00

MrUnknownDE commented

2026-04-05 16:27:05 +02:00

Originally created by @jnovinger on 2/13/2026

Fixes: #21016

Upgrade django-mptt to 0.18.0 and add the missing composite (tree_id, lft) indexes to all MPTT models.

Root Cause

django-mptt dynamically adds indexes to _meta.indexes via its metaclass, but doesn't update _meta.original_attrs['indexes']. Django's migration autodetector only checks original_attrs, so it never detected the missing indexes for models without an explicit indexes declaration in their Meta class.

This is a known issue: django-mptt/django-mptt#682

Solution

Add an empty indexes = () tuple to each affected model's Meta class. This triggers Django's migration detection for the dynamically-added MPTT indexes. We cannot define the indexes explicitly because the MPTT fields (tree_id, lft) don't exist when the Meta class is evaluated.

Affected Models (11)

Region, SiteGroup, Location
DeviceRole, Platform
ModuleBay, InventoryItem, InventoryItemTemplate
TenantGroup, ContactGroup
WirelessLANGroup

Changes

Upgrade django-mptt 0.17.0 → 0.18.0
Add indexes = () with explanatory comment to 9 model Meta classes
3 new migrations adding composite indexes to all 11 MPTT models

*Originally created by @jnovinger on 2/13/2026* ### Fixes: #21016 Upgrade django-mptt to 0.18.0 and add the missing composite `(tree_id, lft)` indexes to all MPTT models. ### Root Cause django-mptt dynamically adds indexes to `_meta.indexes` via its metaclass, but doesn't update `_meta.original_attrs['indexes']`. Django's migration autodetector only checks `original_attrs`, so it never detected the missing indexes for models without an explicit `indexes` declaration in their Meta class. This is a known issue: django-mptt/django-mptt#682 ### Solution Add an empty `indexes = ()` tuple to each affected model's Meta class. This triggers Django's migration detection for the dynamically-added MPTT indexes. We cannot define the indexes explicitly because the MPTT fields (`tree_id`, `lft`) don't exist when the Meta class is evaluated. ### Affected Models (11) - Region, SiteGroup, Location - DeviceRole, Platform - ModuleBay, InventoryItem, InventoryItemTemplate - TenantGroup, ContactGroup - WirelessLANGroup ### Changes - Upgrade django-mptt 0.17.0 → 0.18.0 - Add `indexes = ()` with explanatory comment to 9 model Meta classes - 3 new migrations adding composite indexes to all 11 MPTT models

MrUnknownDE closed this issue

2026-04-05 16:27:05 +02:00

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main

21455-sql-indexes-audit

21357-register-model-actions

feature

20924-plugin-ui-components

21766-improve-test-coverage-for-sortable-table-columns

21157-export-template-public-models

21025-pre-render-config-contexts

21364-swagger

feature-ip-prefix-link

20911-dropdown-3

fix_module_substitution

21160-filterset

20911-dropdown-2

20044-elevation-stuck-lightmode

7604-filter-modifiers-v3

20660-script-load

19724-graphql

14884-script

19720-macaddress-interface-generic-relation

fix-19669-api-image-download

7604-filter-modifiers

19275-fixes-interface-bulk-edit

fix-17794-get_field_value_return_list

11507-show-aggregate-and-rir-on-api

9583-add_column_specific_search_field_to_tables

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Reference: github/netbox#354