Grafana
Grafana is a popular observability and monitoring application used to visualize data and has an extensive ecosystem of widgets and plugins. QuestDB supports connecting to Grafana via the Postgres endpoint.
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Prerequisites- Grafana should be installed and running.
- QuestDB should be installed and running via Docker, the binaries or Homebrew for macOS users.
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Add a data source- Open Grafana's UI (by default available at
http://localhost:3000
) - Go to the
Configuration
section and click onData sources
- Click
Add data source
- Choose the
PostgreSQL
plugin and configure it with the following settings:
- When adding a panel, use the "text edit mode" by clicking the pencil icon and adding a query
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Global variablesTo simplify queries which have dynamic elements such as date range filters, the query can contain global variables which are documented in the Grafana reference documentation.
$__timeFilter(timestamp)
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This variable allows filtering results by sending a start-time and end-time to QuestDB. This expression evaluates to:
$__interval
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This variable calculates a dynamic interval based on the time range applied to the dashboard. By using this function, the sampling interval changes automatically as the user zooms in and out of the panel.