chore: improve query performance

[ngovinh2k2]

What?

Improve the query performance

Why?

How?

Testing?

• Functional Testing
• Security
• Performance
• Error Handling
• Code Quality
• Documentation
• Database
• Deployment
• Final Review

Anything Else?

[gemini-code-assist]

Code Review

This pull request introduces database query optimizations across several services and views, notably by prefetching organization settings and themes to prevent N+1 queries, and using bulk_create for policy generation. Feedback suggests avoiding the use of Django's private _prefetched_objects_cache in favor of the public all() API, simplifying the prefetch_related lookup in views.py to remove redundant Prefetch objects and unused imports, and returning the result of bulk_create directly to ensure primary keys are consistently populated.

Important

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For more details on the timeline and next steps, please review the Help Documentation.

[gemini-code-assist]

Accessing Django's private _prefetched_objects_cache attribute is fragile and can break in future Django updates. Instead, you can use the public setting.themes.all() API. If the themes relation has been prefetched, Django will automatically use the prefetched cache without hitting the database. If it hasn't been prefetched, it will perform a query to fetch the themes. Since an organization setting typically has very few themes (e.g., light and dark), fetching all of them is highly efficient and much more maintainable.

Suggested change

	themes = getattr(setting, "_prefetched_objects_cache", {}).get("themes")
	if themes is not None:
	theme = next((item for item in themes if item.theme_key == theme_key), None)
	else:
	theme = setting.themes.filter(theme_key=theme_key).first()
	theme = next((item for item in setting.themes.all() if item.theme_key == theme_key), None)

[gemini-code-assist]

Using Prefetch with a default queryset (OrganizationTheme.objects.all()) is redundant here. You can simplify the prefetch_related call by passing the lookup path as a string. This is cleaner, more readable, and avoids unnecessary imports.

    queryset = OrganizationEmail.objects.select_related(
        "organization",
        "organization__organization_settings",
    ).prefetch_related(
        "organization__organization_settings__themes"
    )

[gemini-code-assist]

Since Prefetch and OrganizationTheme are no longer needed after simplifying the queryset, their imports can be safely removed to keep the file clean.

Suggested change

	from django.db.models import Prefetch
	from django_filters.rest_framework import DjangoFilterBackend
	from rest_framework.filters import OrderingFilter
	from apps.custom_email.models import OrganizationEmail
	from apps.custom_email.serializers import OrganizationEmailSerializer
	from apps.organization_setting.models import OrganizationTheme
	from django_filters.rest_framework import DjangoFilterBackend
	from rest_framework.filters import OrderingFilter
	from apps.custom_email.models import OrganizationEmail
	from apps.custom_email.serializers import OrganizationEmailSerializer

[gemini-code-assist]

Django's bulk_create returns a list of the created objects with their primary keys populated (on supported databases like PostgreSQL). Returning the original organization_policies list directly is risky because the objects in the original list are not guaranteed to have their primary keys set in-place across all environments or database backends (e.g., during testing with SQLite). Returning the result of bulk_create ensures that the primary keys are always populated in the returned list.

Suggested change

	def create_default_policies(organization):
	organization_policies = []
	for policy in default_policies:
	organization_policy = OrganizationPolicy(**policy, organization=organization)
	organization_policy.save()
	organization_policies.append(organization_policy.pk)
	organization_policies = [
	OrganizationPolicy(**policy, organization=organization)
	for policy in default_policies
	]
	OrganizationPolicy.objects.bulk_create(organization_policies)
	return organization_policies
	def create_default_policies(organization):
	organization_policies = [
	OrganizationPolicy(**policy, organization=organization)
	for policy in default_policies
	]
	return OrganizationPolicy.objects.bulk_create(organization_policies)