• Product
  • Pricing
  • Docs
  • Using PostHog
  • Community
  • Company
  • Login
  • Docs

  • Overview
    • Quickstart with PostHog Cloud
    • Overview
    • Open-Source
      • Disclaimer
      • Deployment
      • Support
    • Enterprise
      • Overview
      • Support
      • Hosting Costs
        • AWS
        • Azure
        • DigitalOcean
        • Google Cloud Platform
        • EU Hosting Companies
        • Other platforms
      • Instance settings
      • Environment variables
      • Securing PostHog
      • Monitoring with Grafana
      • Running behind a proxy
      • Configuring email
      • Helm chart configuration
      • Deploying ClickHouse using Altinity.Cloud
      • Configuring Slack
      • Overview
        • Overview
        • Upgrade notes
        • Overview
        • 0001-events-sample-by
        • 0002_events_sample_by
        • 0003_fill_person_distinct_id2
        • ClickHouse
          • Backup
          • Debug hanging / freezing process
          • Horizontal scaling (Sharding & replication)
          • Kafka Engine
          • Resize disk
          • Restore
          • Vertical scaling
        • Kafka
          • Resize disk
          • Log retention
        • PostgreSQL
          • Resize disk
          • Troubleshooting long-running migrations
        • Plugin server
          • Overview
          • Ingestion lag
          • Jobs not executing
          • Scheduled tasks not executing
        • MinIO
        • Redis
        • Zookeeper
      • Disaster recovery
    • Troubleshooting and FAQs
    • Overview
    • Ingest live data
    • Ingest historical data
    • Identify users
    • User properties
    • Using a CDP
    • Deploying a reverse proxy
    • Library comparison
    • Badge
    • Browser extensions
      • Snippet installation
      • Android
      • iOS
      • JavaScript
      • Flutter
      • React Native
      • Node.js
      • Go
      • Python
      • Rust
      • Java
      • PHP
      • Ruby
      • Elixir
      • Docusaurus v2
      • Gatsby
      • Google Tag Manager
      • Next.js
      • Nuxt.js
      • Retool
      • RudderStack
      • Segment
      • Sentry
      • Slack
      • Shopify
      • WordPress
      • Message formatting
      • Microsoft Teams
      • Slack
      • Discord
    • Migrate between PostHog instances
    • Migrate from Amplitude
    • Migrate to PostHog Cloud EU
    • To another self-hosted instance
    • Export your events
    • Overview
    • Tutorial
    • Troubleshooting
    • Developer reference
    • Using the PostHog API
    • Jobs
    • Testing
    • TypeScript types
    • Overview
    • POST-only public endpoints
    • Actions
    • Annotations
    • Cohorts
    • Dashboards
    • Event definitions
    • Events
    • Experiments
    • Feature flags
    • Funnels
    • Groups
    • Groups types
    • Insights
    • Invites
    • Members
    • Persons
    • Plugin configs
    • Plugins
    • Projects
    • Property definitions
    • Session recordings
    • Trends
    • Users
    • Data model
    • Overview
    • Data model
    • Ingestion pipeline
    • ClickHouse
    • Querying data
    • Overview
    • GDPR guidance
    • HIPAA guidance
    • CCPA guidance
    • SOC 2
    • Data egress & compliance
    • Data deletion
    • Overview
    • Code of conduct
    • Recognizing contributions
  • Using PostHog

  • Table of contents
      • Dashboards
      • Funnels
      • Group Analytics
      • Insights
      • Lifecycle
      • Path analysis
      • Retention
      • Stickiness
      • Trends
      • Heatmaps
      • Session Recording
      • Correlation Analysis
      • Experimentation
      • Feature Flags
      • Actions
      • Annotations
      • Cohorts
      • Data Management
      • Events
      • Persons
      • Sessions
      • UTM segmentation
      • Team collaboration
      • Organizations & projects
      • Settings
      • SSO & SAML
      • Toolbar
      • Notifications & alerts
    • Overview
      • Amazon Kinesis Import
      • BitBucket Release Tracker
      • Event Replicator
      • GitHub Release Tracker
      • GitHub Star Sync
      • GitLab Release Tracker
      • Heartbeat
      • Ingestion Alert
      • Email Scoring
      • n8n Connector
      • Orbit Connector
      • Redshift Import
      • Rudderstack Import
      • Segment Connector
      • Shopify Connector
      • Stripe Connector
      • Twitter Followers Tracker
      • Zendesk Connector
      • Airbyte Exporter
      • Amazon S3 Export
      • Avo Inspector
      • BigQuery Export
      • Customer.io Connector
      • Databricks Export
      • Engage Connector
      • GCP Pub/Sub Connector
      • Google Cloud Storage Export
      • Hubspot Connector
      • Intercom Connector
      • PagerDuty Connector
      • PostgreSQL Export
      • Redshift Export
      • RudderStack Export
      • Salesforce Connector
      • Sendgrid Connector
      • Sentry Connector
      • Snowflake Export
      • Twilio Connector
      • Variance Connector
      • Pace Integration
      • Zapier Connector
      • Downsampler
      • Event Sequence Timer
      • First Time Event Tracker
      • Property Filter
      • Property Flattener
      • Schema Enforcer
      • Taxonomy Standardizer
      • Unduplicator
      • Advanced GeoIP Enricher
      • Automatic Cohort Creator
      • Currency Normalizer
      • GeoIP Enricher
      • Timestamp Parser
      • URL Normalizer
      • User Agent Populator
      • Pineapple Mode
  • Tutorials
    • Actions
    • Apps
    • Cohorts
    • Configuration
    • Data management
    • Dashboards
    • Experimentation
    • Feature flags
    • Funnels
    • Group analytics
    • Heatmaps
    • Insights
    • Path analysis
    • Retention
    • Session recording
    • Toolbar
    • Trends
  • Support
  • Glossary
  • Docs

  • Overview
    • Quickstart with PostHog Cloud
    • Overview
    • Open-Source
      • Disclaimer
      • Deployment
      • Support
    • Enterprise
      • Overview
      • Support
      • Hosting Costs
        • AWS
        • Azure
        • DigitalOcean
        • Google Cloud Platform
        • EU Hosting Companies
        • Other platforms
      • Instance settings
      • Environment variables
      • Securing PostHog
      • Monitoring with Grafana
      • Running behind a proxy
      • Configuring email
      • Helm chart configuration
      • Deploying ClickHouse using Altinity.Cloud
      • Configuring Slack
      • Overview
        • Overview
        • Upgrade notes
        • Overview
        • 0001-events-sample-by
        • 0002_events_sample_by
        • 0003_fill_person_distinct_id2
        • ClickHouse
          • Backup
          • Debug hanging / freezing process
          • Horizontal scaling (Sharding & replication)
          • Kafka Engine
          • Resize disk
          • Restore
          • Vertical scaling
        • Kafka
          • Resize disk
          • Log retention
        • PostgreSQL
          • Resize disk
          • Troubleshooting long-running migrations
        • Plugin server
          • Overview
          • Ingestion lag
          • Jobs not executing
          • Scheduled tasks not executing
        • MinIO
        • Redis
        • Zookeeper
      • Disaster recovery
    • Troubleshooting and FAQs
    • Overview
    • Ingest live data
    • Ingest historical data
    • Identify users
    • User properties
    • Using a CDP
    • Deploying a reverse proxy
    • Library comparison
    • Badge
    • Browser extensions
      • Snippet installation
      • Android
      • iOS
      • JavaScript
      • Flutter
      • React Native
      • Node.js
      • Go
      • Python
      • Rust
      • Java
      • PHP
      • Ruby
      • Elixir
      • Docusaurus v2
      • Gatsby
      • Google Tag Manager
      • Next.js
      • Nuxt.js
      • Retool
      • RudderStack
      • Segment
      • Sentry
      • Slack
      • Shopify
      • WordPress
      • Message formatting
      • Microsoft Teams
      • Slack
      • Discord
    • Migrate between PostHog instances
    • Migrate from Amplitude
    • Migrate to PostHog Cloud EU
    • To another self-hosted instance
    • Export your events
    • Overview
    • Tutorial
    • Troubleshooting
    • Developer reference
    • Using the PostHog API
    • Jobs
    • Testing
    • TypeScript types
    • Overview
    • POST-only public endpoints
    • Actions
    • Annotations
    • Cohorts
    • Dashboards
    • Event definitions
    • Events
    • Experiments
    • Feature flags
    • Funnels
    • Groups
    • Groups types
    • Insights
    • Invites
    • Members
    • Persons
    • Plugin configs
    • Plugins
    • Projects
    • Property definitions
    • Session recordings
    • Trends
    • Users
    • Data model
    • Overview
    • Data model
    • Ingestion pipeline
    • ClickHouse
    • Querying data
    • Overview
    • GDPR guidance
    • HIPAA guidance
    • CCPA guidance
    • SOC 2
    • Data egress & compliance
    • Data deletion
    • Overview
    • Code of conduct
    • Recognizing contributions
  • Using PostHog

  • Table of contents
      • Dashboards
      • Funnels
      • Group Analytics
      • Insights
      • Lifecycle
      • Path analysis
      • Retention
      • Stickiness
      • Trends
      • Heatmaps
      • Session Recording
      • Correlation Analysis
      • Experimentation
      • Feature Flags
      • Actions
      • Annotations
      • Cohorts
      • Data Management
      • Events
      • Persons
      • Sessions
      • UTM segmentation
      • Team collaboration
      • Organizations & projects
      • Settings
      • SSO & SAML
      • Toolbar
      • Notifications & alerts
    • Overview
      • Amazon Kinesis Import
      • BitBucket Release Tracker
      • Event Replicator
      • GitHub Release Tracker
      • GitHub Star Sync
      • GitLab Release Tracker
      • Heartbeat
      • Ingestion Alert
      • Email Scoring
      • n8n Connector
      • Orbit Connector
      • Redshift Import
      • Rudderstack Import
      • Segment Connector
      • Shopify Connector
      • Stripe Connector
      • Twitter Followers Tracker
      • Zendesk Connector
      • Airbyte Exporter
      • Amazon S3 Export
      • Avo Inspector
      • BigQuery Export
      • Customer.io Connector
      • Databricks Export
      • Engage Connector
      • GCP Pub/Sub Connector
      • Google Cloud Storage Export
      • Hubspot Connector
      • Intercom Connector
      • PagerDuty Connector
      • PostgreSQL Export
      • Redshift Export
      • RudderStack Export
      • Salesforce Connector
      • Sendgrid Connector
      • Sentry Connector
      • Snowflake Export
      • Twilio Connector
      • Variance Connector
      • Pace Integration
      • Zapier Connector
      • Downsampler
      • Event Sequence Timer
      • First Time Event Tracker
      • Property Filter
      • Property Flattener
      • Schema Enforcer
      • Taxonomy Standardizer
      • Unduplicator
      • Advanced GeoIP Enricher
      • Automatic Cohort Creator
      • Currency Normalizer
      • GeoIP Enricher
      • Timestamp Parser
      • URL Normalizer
      • User Agent Populator
      • Pineapple Mode
  • Tutorials
    • Actions
    • Apps
    • Cohorts
    • Configuration
    • Data management
    • Dashboards
    • Experimentation
    • Feature flags
    • Funnels
    • Group analytics
    • Heatmaps
    • Insights
    • Path analysis
    • Retention
    • Session recording
    • Toolbar
    • Trends
  • Support
  • Glossary
  • Docs
  • Self-host
  • Runbook
  • Async migrations
  • 0001-events-sample-by

Migration guide - 0001_events_sample_by

Last updated: Aug 09, 2022

0001_events_sample_by is a no-op test async migration. Note that on PostHog version 1.32 we automatically continue to run other migrations after a successful completion.

Questions?

Was this page useful?

Next article

Migration guide - 0002_events_sample_by

0002_events_sample_by is an async migration added to change the SAMPLE BY and ORDER BY clauses of our events table in ClickHouse. There were 2 important reasons for doing this: Performance: The new schema leads to a performance (speed) improvement for various PostHog queries Upgrading ClickHouse: Changing the schema was necessary to unblock the upgrading of ClickHouse, which is something we aim to complete in PostHog version 1.33.0 and can also bring massive performance improvements. Note…

Read next article

Author

  • Paul Hultgren
    Paul Hultgren

Share

  • Product

  • Overview
  • Pricing
  • Product analytics
  • Session recording
  • A/B testing
  • Feature flags
  • Apps
  • Customer stories
  • PostHog vs...
  • Docs

  • Quickstart guide
  • Self-hosting
  • Installing PostHog
  • Building an app
  • API
  • Webhooks
  • How PostHog works
  • Data privacy
  • Using PostHog

  • Product manual
  • Apps manuals
  • Tutorials
  • Community

  • Questions?
  • Product roadmap
  • Contributors
  • Partners
  • Newsletter
  • Merch
  • PostHog FM
  • PostHog on GitHub
  • Handbook

  • Getting started
  • Company
  • Strategy
  • How we work
  • Small teams
  • People & Ops
  • Engineering
  • Product
  • Design
  • Marketing
  • Customer success
  • Company

  • About
  • Team
  • Investors
  • Press
  • Blog
  • FAQ
  • Support
  • Careers
© 2023 PostHog, Inc.
  • Code of conduct
  • Privacy policy
  • Terms