6 docs tagged with "Stream Data"

Aggregation queries compute summary values (averages, totals, extremes) across time-series data points instead of returning individual rows. Use these when you need calculated metrics rather than raw data — for example, the average voltage over the last hour or the total energy produced per machine.

A downsampling query reduces the density of time-series data by dividing a time range into equal-sized buckets and applying an aggregation function to each bucket. This is essential for visualizing large datasets on dashboards and charts — instead of transferring thousands of raw data points, you get a manageable number of summarized values.

Persisted queries are saved query definitions stored as runtime entities. Instead of specifying all query parameters every time, you create a query definition once and execute it by its rtId. This is useful for dashboard widgets, recurring reports, and any scenario where the same query needs to be executed repeatedly.

A simple query retrieves raw time-series rows from CrateDB. You choose which columns to return and can apply filters, sorting, and time range restrictions. This is the most fundamental stream data query type — use it when you need individual data points rather than aggregated summaries.

A Stream Data Archive is the unit of configuration and storage for time-series data in OctoMesh. Each archive is a versioned, typed, per-tenant CrateDB table that captures a curated set of attribute paths from a Construction Kit type. Archives have a strict lifecycle (Created → Activated → Disabled / Failed), an immutable schema once activated, and a three-tier activation gate (instance → tenant → archive) that determines whether the data plane is open.

The Stream Data Archives section of the Refinery Studio lets you create and manage the time-series archives that capture data into CrateDB. Each archive defines a CK type, a curated list of attribute paths, and a status — and the studio walks you through every state transition (Activate, Disable, Enable, Retry, Delete) with confirmation dialogs.