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

# Rollup Aggregation Stage

export const schema = {
  "type": "object",
  "title": "Rollup Aggregation",
  "description": "Rollup stage to aggregate Solr results in the format of List<DocumentResult>",
  "required": ["key", "resultKey", "rollupField"],
  "properties": {
    "skip": {
      "type": "boolean",
      "title": "Skip This Stage",
      "description": "Set to true to skip this stage.",
      "default": false,
      "hints": ["advanced"]
    },
    "label": {
      "type": "string",
      "title": "Label",
      "description": "A unique label for this stage.",
      "hints": ["advanced"],
      "maxLength": 255
    },
    "condition": {
      "type": "string",
      "title": "Condition",
      "description": "Define a conditional script that must result in true or false. This can be used to determine if the stage should process or not.",
      "hints": ["code", "code/javascript", "advanced"]
    },
    "key": {
      "type": "string",
      "title": "Key",
      "description": "The key name to use from context to read Solr results."
    },
    "resultKey": {
      "type": "string",
      "title": "Result Key",
      "description": "The key name to which the results should be saved."
    },
    "rollupField": {
      "type": "string",
      "title": "Rollup Field",
      "description": "The field to rollup on."
    },
    "excludeResultsKey": {
      "type": "string",
      "title": "Results to Exclude",
      "description": "The key containing a set of results to exclude from this rollup."
    },
    "weightField": {
      "type": "string",
      "title": "Weight Field",
      "description": "The numerical field to consider as weight."
    },
    "weightFunction": {
      "type": "string",
      "title": "Weight Arithmetic Function",
      "description": "The arithmetic function to use for weight fields on documents with same rollup field.",
      "enum": ["sum", "mean", "max", "min", "stddev", "variance", "geoMean", "sumOfSquares", "sumOfLogs"],
      "default": "sum"
    },
    "maxRows": {
      "type": "integer",
      "title": "Max rows",
      "description": "The maximum number of results to return",
      "default": 10
    },
    "sort": {
      "type": "boolean",
      "title": "Sort results",
      "description": "If enabled, the output is sorted based on weight field if it is not null",
      "default": true
    },
    "weightExpression": {
      "type": "string",
      "title": "Final Boost Weight Expression",
      "description": "Optional expression to compute the final boost weight using a combination of fields returned by Solr, such as score and weight_d",
      "hints": ["advanced"]
    }
  },
  "category": "Other",
  "categoryPriority": 1,
  "unsafe": false
};

export const SchemaParamFields = ({schema}) => {
  const sanitize = str => {
    if (typeof str !== "string") return str;
    return str.replace(/^"(.*)"$/s, "$1").replace(/\\/g, "").replace(/"/g, "'");
  };
  const formatDescription = str => {
    const s = sanitize(str);
    return (/[.!?]\)*$/).test(s) ? s : `${s}.`;
  };
  const {description, properties = {}, required: requiredProps = []} = schema;
  const visibleProps = useMemo(() => Object.entries(properties).filter(([, prop]) => !prop.hints?.includes("hidden")), [properties]);
  return <div>
      {description && <p>{formatDescription(description)}</p>}

      {visibleProps.map(([name, prop]) => {
    const isRequired = requiredProps.includes(name);
    const hasDefault = prop.default !== undefined;
    const rawDefault = prop.default;
    const isComplexDefault = hasDefault && (typeof rawDefault === "object" || typeof rawDefault === "string" && (rawDefault.length > 20 || rawDefault.includes('"')));
    const fieldProps = {
      key: name,
      body: prop.title || name,
      type: prop.type,
      ...prop.title && ({
        post: [<><span className="text-stone-400 dark:text-stone-500">API property: </span>{name}</>]
      }),
      ...isRequired && ({
        required: true
      }),
      ...!isComplexDefault && hasDefault ? {
        default: sanitize(String(rawDefault))
      } : {}
    };
    const isObject = prop.type === "object" && prop.properties;
    const isArrayOfObjects = prop.type === "array" && prop.items?.type === "object" && prop.items.properties;
    return <ParamField {...fieldProps}>
            {prop.description && <p>{formatDescription(prop.description)}</p>}

            {isComplexDefault && <div className="flex">
                <p>
                  <strong>Default:</strong>
                </p>
                <pre className="!my-0">
                  <code>
                    {JSON.stringify(rawDefault, null, 2)}
                  </code>
                </pre>
              </div>}

            {isArrayOfObjects && <div className="flex">
              <p>
                <strong>Object attributes:</strong>
              </p>
              <pre className="!my-0">
                <code>
                  {'{\n'}
                  {Object.entries(prop.items.properties).map(([iname, iprop]) => <>
                      {`  ${iname}`}
                      {prop.items?.required?.includes(iname) && <span style={{
      color: 'red'
    }}> required</span>}
                      {`: {\n    display name: ${sanitize(iprop.title || '')}\n    type: ${iprop.type}\n  }\n`}
                    </>)}
                  {'}'}
                </code>
              </pre>
              </div>}

            {isObject && <Expandable title="properties">
                <SchemaParamFields schema={{
      properties: prop.properties,
      required: prop.required
    }} />
              </Expandable>}
          </ParamField>;
  })}
    </div>;
};

export const LwTemplate = ({title = "Key questions to get you started", icon = "sparkles", cta = "Powered by Agent Studio", linkHref = "https://lucidworks.com/demo/?utm_source=docs&utm_medium=referral&utm_campaign=docs_cta_ai"}) => {
  const [isLoaded, setIsLoaded] = useState(false);
  useEffect(() => {
    const timer = setTimeout(() => {
      setIsLoaded(true);
    }, 500);
    return () => clearTimeout(timer);
  }, []);
  return <div className="lw-template-container">
      <Card title={title} icon={icon}>
        {isLoaded && <span dangerouslySetInnerHTML={{
    __html: `<lw-template id="a029c1a9-28be-427e-b0e1-5d918920246a"></lw-template
            >`
  }} />}
        <Link href={linkHref} className="agent-studio-link text-left text-gray-600 gap-2 dark:text-gray-400 text-sm font-medium flex flex-row items-center hover:text-primary dark:hover:text-primary-light group-hover:text-primary group-hover:dark:text-primary-light">Powered by Lucidworks Agent Studio</Link>
      </Card>
    </div>;
};

[localhost link]: http://localhost:3000/docs/4/fusion-server/reference/pipeline-stages/query/rollup-aggregator-query-stage

[mintlify link]: https://doc.lucidworks.com/docs/4/fusion-server/reference/pipeline-stages/query/rollup-aggregator-query-stage

[old doc.lw link]: https://doc.lucidworks.com/fusion/5.9/282

The Rollup Aggregation query pipeline stage (previously called the Rollup Aggregator stage) is used to roll up Solr results from a context variable. In the REST API, this stage type is named `rollup-rec-aggr`.

This stage reads the Solr results (`SolrResponse.class`) from the context and rolls up over a single field product a list of unique IDs and also aggregates the weights (any numeric field in Solr) for those IDs using any of the statistical aggregation functions available. The result from aggregation is saved back in the context and can be used later in a Parameterized Boosting stage.

<LwTemplate />

## Configuration

<Tip>
  When entering configuration values in the UI, use *unescaped* characters, such as `\t` for the tab character. When entering configuration values in the API, use *escaped* characters, such as `\\t` for the tab character.
</Tip>

<SchemaParamFields schema={schema} />