data structure FirstRank-OpenSearch(Open Search)-阿里云帮助中心

A FirstRank object defines the rough sort expression configured for a version of an OpenSearch application.

Open Search supports two expression types:

STRUCT — defines the expression as a structured array of weighted attributes or feature functions. This is the default.
STRING — defines the expression as a custom formula string, such as random()*100+now().

Examples

STRUCT type — a structured expression using the static BM25 scoring function:

{
  "name": "default",
  "description": "",
  "active": true,
  "type": "STRUCT",
  "meta": [
    {
      "attribute": "static_bm25()",
      "arg": "",
      "weight": 10
    }
  ]
}

STRING type — a custom formula expression:

{
  "name": "my_demo",
  "description": "",
  "active": false,
  "type": "STRING",
  "meta": "random()*100+now()"
}

Structure

Field	Type	Description
`name`	String	The name of the expression.
`description`	String	A description of the expression.
`active`	Boolean	Indicates whether the rough sort expression is the default one.
`type`	String	The expression type. Valid values: `STRUCT` (default), `STRING`.
`meta`	Array or String	The content of the expression. When `type` is `STRUCT`, this is an array of attribute objects (see below). When `type` is `STRING`, this is a formula string.

meta fields (when type is STRUCT)

Field	Type	Description
`[].attribute`	String	The attribute, feature function, or field to score against. For supported values, see Rough sort functions.
`[].arg`	String	Parameters passed to the function specified in `attribute`. For details, see Rough sort functions.
`[].weight`	Number	The weight applied to this attribute. Valid values: –100000 to 100000, excluding 0.