Experiments HogQL rewrite

[jurajmajerik]

Trends

• Set up a query runner
• Retrieve Experiment
• Prepare Trend query
  • Display type
  • Start/end dates
  • Flag breakdown
• Prepare exposure query
  • Events/actions
  • Start/end dates
  • Flag breakdown
  • Default feature flag exposure filter
• Handle math aggregation path
• Add statistical calculations
• Custom errors
• Filter out test accounts
• Copy over existing tests

Funnels

• Set up a query runner
• Retrieve Experiment
• Prepare Funnel query
  • Display type
  • Start/end dates
  • Flag breakdown
  • Reset properties
• Add statistical calculations
• Custom errors
• Filter out test accounts
• Copy over existing tests

Schema migration

• Add a metrics field
• Migrate Experiment records

Frontend

• Call /query - primary metric
• Call /query - secondary metrics
• Ensure backwards compatibility (transform filters to query)
• Retrieve from cache vs. recalculate

Debug info

- [ ] PostHog Cloud, Debug information: [please copy/paste from https://us.posthog.com/settings/project-details#variables]
- [ ] PostHog Hobby self-hosted with `docker compose`, version/commit: [please provide]
- [ ] PostHog self-hosted with Kubernetes (deprecated, see [`Sunsetting Kubernetes support`](https://posthog.com/blog/sunsetting-helm-support-posthog)), version/commit: [please provide]

[abigailbramble]

https://posthoghelp.zendesk.com/agent/tickets/19665 and https://posthoghelp.zendesk.com/agent/tickets/19431
both seeing experiment results affected by anonymous events.
It looks like experiments are unintentionally filtering out anonymous people: see this thread
This will be fixed by the above migration.