feat(dashboards): add concurrent indexes for dashboard widget tiles (5/11)

[MattPua]

Problem

Widget tiles will be queried by widget_id; the index must be built concurrently to avoid blocking writes on posthog_dashboardtile.

This PR is 5/10 in the dashboard widgets Graphite stack.

Depends on: PR 4 (validated constraints)

Changes

• Migration 0011_dashboardtile_widget_id_idx — concurrent index on widget_id plus partial unique (dashboard, widget) constraint
• Final DashboardTile Meta constraints including unique_dashboard_widget

How did you test this code?

• Agent: did not run manual migrations locally
• Uses CREATE INDEX CONCURRENTLY pattern from PostHog migration conventions

👉 Stay up-to-date with PostHog coding conventions for a smoother review.

Publish to changelog?

no

Docs update

skip-inkeep-docs

🤖 Agent context

• Index migration is its own PR because concurrent index builds are long-running and should be monitored independently
• Completes the schema foundation; feature code begins in PR 6

[MattPua]

• feat(dashboards): add widget registry, run_widgets, and dashboard widget API (6/11) #60494 : 2 dependent PRs (#60495 , #60523 )
• feat(dashboards): add concurrent indexes for dashboard widget tiles (5/11) #60493 👈 (View in Graphite)
• feat(dashboards): validate dashboard tile widget constraints (4/11) #60492
• feat(dashboards): extend dashboard tile exclusivity check for widgets (3/11) #60491
• feat(dashboards): add dashboard tile widget_id column (2/11) #60490
• feat(dashboards): add DashboardWidget model and table migration (1/11) #60489
• master

This stack of pull requests is managed by Graphite. Learn more about stacking.

[tests-posthog]

⏭️ Skipped snapshot commit because branch advanced to 753582f while workflow was testing e509ef4.

The new commit will trigger its own snapshot update workflow.

If you expected this workflow to succeed: This can happen due to concurrent commits. To get a fresh workflow run, either:

• Merge master into your branch, or
• Push an empty commit: git commit --allow-empty -m 'trigger CI' && git push

[github-actions]

Migration SQL Changes

Hey 👋, we've detected some migrations on this PR. Here's the SQL output for each migration, make sure they make sense:

products/dashboards/backend/migrations/0011_dashboardtile_widget_id_idx.py

--
-- Custom state/database change combination
--
-- (no-op)
--
-- Raw SQL operation
--
CREATE INDEX CONCURRENTLY IF NOT EXISTS "posthog_dashboardtile_widget_id_idx" ON "posthog_dashboardtile" ("widget_id") WHERE "widget_id" IS NOT NULL;
--
-- Raw SQL operation
--
CREATE UNIQUE INDEX CONCURRENTLY IF NOT EXISTS "unique_dashboard_widget" ON "posthog_dashboardtile" ("dashboard_id", "widget_id") WHERE "widget_id" IS NOT NULL;

Last updated: 2026-05-29 20:32 UTC (184fdda)

[github-actions]

🔍 Migration Risk Analysis

We've analyzed your migrations for potential risks.

Summary: 1 Safe | 0 Needs Review | 0 Blocked

✅ Safe

Brief or no lock, backwards compatible

dashboards.0011_dashboardtile_widget_id_idx
  └─ #1 ✅ SeparateDatabaseAndState: Only state operations (no database changes)
  └─ #2 ✅ RunSQL: CREATE INDEX CONCURRENTLY is safe (non-blocking)
  └─ #3 ✅ RunSQL: CREATE INDEX CONCURRENTLY is safe (non-blocking)

Last updated: 2026-05-29 20:32 UTC (184fdda)

[tests-posthog]

Query snapshots: Backend query snapshots updated

Changes: 3 snapshots (3 modified, 0 added, 0 deleted)

What this means:

• Query snapshots have been automatically updated to match current output
• These changes reflect modifications to database queries or schema

Next steps:

• Review the query changes to ensure they're intentional
• If unexpected, investigate what caused the query to change

Review snapshot changes →

[greptile-apps]

_{Reviews (1): Last reviewed commit: "test(backend): update query snapshots" | Re-trigger Greptile}

[tests-posthog]

Query snapshots: Backend query snapshots updated

Changes: 1 snapshots (1 modified, 0 added, 0 deleted)

What this means:

• Query snapshots have been automatically updated to match current output
• These changes reflect modifications to database queries or schema

Next steps:

• Review the query changes to ensure they're intentional
• If unexpected, investigate what caused the query to change

Review snapshot changes →

[tests-posthog]

Query snapshots: Backend query snapshots updated

Changes: 1 snapshots (1 modified, 0 added, 0 deleted)

What this means:

• Query snapshots have been automatically updated to match current output
• These changes reflect modifications to database queries or schema

Next steps:

• Review the query changes to ensure they're intentional
• If unexpected, investigate what caused the query to change

Review snapshot changes →

[tests-posthog]

Query snapshots: Backend query snapshots updated

Changes: 1 snapshots (1 modified, 0 added, 0 deleted)

What this means:

• Query snapshots have been automatically updated to match current output
• These changes reflect modifications to database queries or schema

Next steps:

• Review the query changes to ensure they're intentional
• If unexpected, investigate what caused the query to change

Review snapshot changes →

[MattPua]

Merge activity

• May 29, 8:41 PM UTC: @MattPua merged this pull request with Graphite.

[deployment-status-posthog]

Deploy status

Environment	Status	Deployed At	Workflow
dev	✅ Deployed	2026-05-29 21:17 UTC	Run
prod-us	✅ Deployed	2026-05-29 21:37 UTC	Run
prod-eu	✅ Deployed	2026-05-29 21:44 UTC	Run