Get a randomized sample of rows from a table on this connection. Used by the visualization editor to give sellers data to author against. Query Parameters: schema_name (required): Schema/dataset name table_name (required): Table name limit (optional): Max rows to return (default 1000, max 10000) Returns columnar data — {column_name: [values]} — ready for Plotly's dataSources prop. The actual chart at render time will pull fresh data via the asset's saved SQL; this is only for authoring preview.