class ActivityLog(UUIDTModel):
    class Meta:
        constraints = [
            models.CheckConstraint(
                name="must_have_team_or_organization_id",
                condition=models.Q(team_id__isnull=False) | models.Q(organization_id__isnull=False),
            ),
        ]
        indexes = [
            models.Index(fields=["team_id", "scope", "item_id"]),
            models.Index(
                fields=["organization_id", "scope", "-created_at"],
                name="idx_alog_org_scope_created_at",
                condition=models.Q(detail__isnull=False) & models.Q(detail__jsonb_typeof="object"),
            ),
            models.Index(
                fields=["organization_id"],
                name="idx_alog_org_detail_exists",
                condition=models.Q(detail__isnull=False) & models.Q(detail__jsonb_typeof="object"),
            ),
            # Serves whole-column containment (`detail @> ...`), the only detail lookup an index
            # can answer. Key-path lookups and the `detail::text` search are not GIN-servable
            # under any opclass. `jsonb_path_ops` stores one hash per root-to-leaf path, so it is
            # smaller and cheaper to maintain than `jsonb_ops`, whose only extra operators are the
            # key-existence family (`?`, `?|`, `?&`) that no query path uses. It also stores no
            # entry for a JSON structure that holds no scalar, so containment against an empty
            # object or array (`detail @> '{"changes": []}'`) falls back to a full index scan.
            GinIndex(
                name="idx_alog_detail_gin_path_ops",
                fields=["detail"],
                opclasses=["jsonb_path_ops"],
            ),
…
    activity = models.fields.CharField(max_length=79, null=False)
    # if scoped to a model this activity log holds the id of the model being logged
    # if not scoped to a model this log might not hold an item_id
    # this might be a numerical id, short id, or UUID, so each will be converted to string
    # it will be used to lookup rows with exactly matching item_ids
    # it probably only needs to be 36 characters in order to hold a GUID
    # but 72 may be useful to avoid a migration in future
    item_id = models.fields.CharField(max_length=72, null=True)
    # e.g. FeatureFlags - this will often be the name of a model class
    scope = models.fields.CharField(max_length=79, null=False)
    detail = models.JSONField(encoder=ActivityDetailEncoder, null=True)
    created_at = models.DateTimeField(default=timezone.now)
Warm-up
