> ## Documentation Index
> Fetch the complete documentation index at: https://docs.startree.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Dimension Exploration

Dimension exploration lets you create alerts for a specified dimension or combination of dimensions. See [the procedural doc](/thirdeye/dimension-exploration) if some of these terms don't look familiar.

Dimension exploration uses the **enumerator**, **fork join** and **combiner** operators to build loops inside the detection DAG. Here's a simple pipeline for threshold detection.

```json theme={null}
 "nodes": [
        {
          "name": "enumerator",
          "type": "Enumerator",
          "params": {
            "items": [
              {
                "name":"US Only",
                "params": {
                "queryFilters": " AND country = 'US'",
                  "max": 300000,
                  "min": 100000
                }
              },
              {
                "name": "Overall",
                "params": {
                "queryFilters": "",
                  "max": 900000,
                  "min": 300000
                }
              }
            ]
          }
        },
        {
          "name": "combiner",
          "type": "Combiner"
        },
        {
          "name": "root",
          "type": "ForkJoin",
          "params": {
            "dryRun": false,
            "enumerator": "enumerator",
            "root": "anomalyDetector",
            "combiner": "combiner"
          }
        },
        {
          "name": "anomalyDetector",
          "type": "AnomalyDetector",
          "params": {
            "component.min": "${min}",
            "component.metric": "met",
            "component.monitoringGranularity": "${monitoringGranularity}",
            "component.max": "${max}",
            "anomaly.dataset": "${dataset}",
            "component.timestamp": "ts",
            "anomaly.metric": "${aggregationColumn}",
            "anomaly.source": "threshold-template/root",
            "type": "THRESHOLD"
          },
          "inputs": [
            {
              "targetProperty": "current",
              "sourcePlanNode": "currentDataFetcher",
              "sourceProperty": "currentData"
            }
          ],
          "outputs": []
        },
        {
          "name": "currentDataFetcher",
          "type": "DataFetcher",
          "params": {
            "component.dataSource": "${dataSource}",
            "component.query": "SELECT __timeGroup(\"${timeColumn}\", '${timeColumnFormat}', '${monitoringGranularity}') as ts, ${aggregationFunction}(\"${aggregationColumn}\") as met FROM ${dataset} WHERE __timeFilter(\"${timeColumn}\", '${timeColumnFormat}') ${queryFilters} GROUP BY ts ORDER BY ts LIMIT ${queryLimit}"
          },
          "inputs": [],
          "outputs": [
            {
              "outputKey": "currentData",
              "outputName": "currentData"
            }
          ]
        }
      ]
```

## Enumeration item templatization

This is a simple default enumerator which lays out all the enumeration items.

The same json can be templatized by using thirdeye's ability to replace objects in strings.
In this case, the enumerator node lists all the enumerations and can be split into the template and the value.

The template can expose the items array using a variable `"${enumerationItems}"`.

```json theme={null}
        {
          "name": "enumerator",
          "type": "Enumerator",
          "params": {
            "items": "${enumerationItems}"
          }
        }
```

ThirdEye can detect that `enumerationItems` is an object and replaces the entire string with an object and behaves exactly like the initial pipeline json as shown above.

```json theme={null}
{
  "templateProperties": {
   "enumerationItems": [
     {
       "name":"US Only",
       "params": {
         "queryFilters": " AND country = 'US'",
         "max": 300000,
         "min": 100000
       }
     },
     {
       "name": "Overall",
       "params": {
         "queryFilters": "",
         "max": 900000,
         "min": 300000
       }
     }
   ]
  }
}
```

## Sample Alert

Using these methods, dimension exploration can be templatized and expressed with templateProperties. Here is a sample dimension exploration alert look at pageviews with different combinations of threshold parameters and query filters.

```json theme={null}
{
  "name": "pageviews-dx-country",
  "description": "Sample description payload for testing",
  "template": {
    "name": "startree-threshold-dx"
  },
  "templateProperties": {
    "dataSource": "pinot",
    "dataset": "pageviews",
    "aggregationFunction": "sum",
    "aggregationColumn": "views",
    "monitoringGranularity": "P1D",
    "timeColumn": "date",
    "timeColumnFormat": "1:DAYS:SIMPLE_DATE_FORMAT:yyyyMMdd",
    "max": "${max}",
    "min": "${min}",
    "queryFilters": "${queryFilters}",
    "enumerationItems": [
      {
        "name": "US",
        "params": {
          "queryFilters": " AND country = 'US'",
          "max": 300000,
          "min": 100000
        }
      },
      {
        "name": "Overall",
        "params": {
          "queryFilters": "",
          "max": 900000,
          "min": 300000
        }
      },
      {
        "name": "IN",
        "params": {
          "queryFilters": " AND country = 'IN'",
          "max": 900000,
          "min": 0
        }
      }
    ]
  },
  "cron": "0 0 * * * ? *"
}
```