Out-of-the-Box Merge Algorithms

Smart Mastering provides the following merge algorithms that you can use without having to write any code. A merge algorithm determines which property values from source documents are brought into a merge document. That is, when merging documents A, B, and C, suppose that for a particular property, those documents had values A1, A2, B1, and C1. A merge algorithm will determine which and how many of those values will be in the new document ABC.

In addition to the built-in algorithm, you can write your own custom functions.

Standard Algorithm

Smart Mastering currently provides a standard algorithm, which can be configured for different uses. You can use it by adding XML or JSON similar to the below to your merge options.

<options xmlns="http://marklogic.com/smart-mastering/merging">
  <merging xmlns="http://marklogic.com/smart-mastering/merging">
    <merge property-name="some-property" max-values="1">
        <source name="good-source" weight="2"/>
        <source name="better-source" weight="4"/>
    <merge property-name="another-property" max-values="1">
      <length weight="8" />
  "options": {
    "merging": [
        "propertyName": "some-property",
        "sourceWeights": [
          { "source": { "name": "good-source", "weight": "2" } },
          { "source": { "name": "better-source", "weight": "4" } }
        "propertyName": "another-property",
        "maxValues": "1",
        "length": { "weight": "8" }

Sorting by Source

The standard algorithm will sort the available values and keep the first max-values/maxValues other them. The sort of the values is based on weights for individual sources (where the source is identified by the value at /es:envelope/es:headers/sm:sources/sm:source/*:name for XML and /envelope/headers/sources/source/name for JSON). To sort by source weight, provide the name of the sources from the document headers and a weight. These weights must be castable to xs:double.

Sorting by Length

This algorithm can sort values by how long they are. Consider length here to be a proxy for more complete information. Use the weight setting for length to control how much influence this attribute has.

Sorting by Recency

If the source documents have a dateTime that indicates how recent the data is, the standard algorithm can use that sort values. See https://marklogic-community.github.io/smart-mastering-core/docs/merging-options/#timestamp for information on configuring this feature.

Combining the Sort Factors

The scores for source preference and for value length will be added together. Ties are resolved by the more recent source, if a timestamp location is configured.