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Overview

Many databases store semi-structured data in JSON columns. JSON Column Parsing lets you expand these nested fields into separate, queryable columns - no ETL pipeline needed. Once activated, JSON properties appear as individual columns in your charts and filters. Before: A single metadata column containing {"region": "US", "plan": "pro", "mrr": 450} After: Three separate columns - metadata.region, metadata.plan, metadata.mrr - each usable in axes, filters, and groupings.

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Supported Databases

JSON parsing works with Postgres, BigQuery, ClickHouse, and databases connected via the Data Plane. The system generates the correct JSON extraction syntax for each database type automatically.

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Step 1: Recompute Connection Metadata

Before enabling JSON parsing, make sure your connection metadata is up to date.
  1. Navigate to the Connections page
  2. Find the connection that contains your JSON columns
  3. Click Recompute Metadata
  4. Wait for the metadata refresh to complete
Recompute metadata button on the connections page

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Step 2: Activate JSON Parsing on a Column

After metadata is refreshed, columns containing JSON data will show a type of mixed.
  1. In the metadata viewer, select the table containing your JSON column
  2. Find the column with type mixed
  3. Click the Expose JSON button next to it
  4. A success notification confirms the column is now JSON-parsed
Expose JSON button next to a mixed-type column
Once activated, the button is replaced with a green checkmark and “JSON” label.
Column showing green JSON parsed confirmation

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Step 3: Use JSON Fields in Charts

The parsed JSON properties are now available as separate columns when building charts.
  1. Go to your Dashboard
  2. Create a new chart or edit an existing one
  3. In the Raw Tables section, select the table with the JSON column
  4. Save the chart
When the chart loads, all nested JSON properties appear as individual columns (e.g., metadata.region, metadata.plan).
Chart builder showing expanded JSON properties as separate columns
You can use these expanded columns for:
  • X-Axis and Y-Axis values
  • Group By segmentation
  • Aggregations (sum, count, avg on numeric JSON properties)
Rendered chart using JSON column data

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Step 4: Filter by JSON Fields

Parsed JSON fields also appear in the filter panel, letting users filter dashboards by nested properties.
  1. Open the Filters section of your dashboard or chart
  2. After selecting raw tables, the nested JSON properties appear in the filter column dropdown
  3. Select a JSON property to filter by (e.g., metadata.region)
  4. Choose a filter type (equals, contains, etc.) and set the value
Filter panel showing JSON properties as filterable columns
All standard filter types work with JSON fields:
  • Input filters (equals, contains, starts with)
  • Select filters (single and multi-select)
  • Number filters (greater than, less than, equal to) for numeric JSON properties
  • Date filters for date-typed JSON properties

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Notes

  • JSON parsing happens at query time. The original JSON column is replaced by its expanded properties in the chart’s SQL query.
  • If the JSON structure changes (new keys added), recompute metadata and re-save the chart to pick up new fields.
  • Column names use dot notation (e.g., metadata.region) to indicate nesting.
  • Deeply nested JSON is supported - each level is separated by dots (e.g., metadata.address.city).