Using dynamic fields

Using dynamic fields, you can index content in fields that are not explicitly defined by the schema. A common use case for dynamic fields is to identify fields that should not be indexed or to implement a schema-less index.

Search schema fields that are dynamic and multiValued are not supported in CQL-based search indexes.

Best practices

  • Avoid or limit the use of dynamic fields.

    Apache Lucene® allocates memory for each unique field (column) name. For example, for a row with columns A, B, C, and another row with B, D, E, Lucene allocates 5 chunks of memory. For millions of rows, the heap is unwieldy.

  • Instead of using dynamic fields, use a default query field, and then perform queries against the combined field.

  • Use the FieldInputTransformer (FIT) API.

Spatial subfields prefix naming conventions

Dynamic fields for spatial subfields use prefix naming conventions to enable using map types to store geospatial data:

    <fieldType class="solr.LatLonType" multiValued="false" name="LatLonType" subFieldPrefix="llt_"/>
    <fieldType name="tdouble" class="solr.TrieDoubleField" precisionStep="8" positionIncrementGap="0"/>
    <dynamicField indexed="true" name="latmap*" stored="true" type="LatLonType"/>
    <dynamicField name="llt_*"  type="tdouble"  indexed="true"  stored="true"/>

To use a dynamic field

  • Include an Apache Solr™ dynamic field in the search index schema.

    Name the field using a wildcard at the beginning or end of the field. For example, an asterisk prefix or suffix in the field name in the schema designates a dynamic field:

    • dyna_*

    • *_s

  • To define the map collection column in CQL, use the same base name (no asterisk) that you used for the field in search index schema.

    For example, use dyna_* in the search index schema and dyna_ for the name of the CQL map collection.

  • Use type text for the map key:

    CREATE TABLE my_dynamic_table (
      . . .
      dyna_ map<text, int>,
      . . .
  • Using CQL, insert data into the map using the base name as a prefix or suffix in the first component of each map pair:

    { <prefix_literal : literal, prefix_literal : literal, . . .> }

    The CQL map looks like:

    'dyna_' : {dyna_1 : 1, dyna_2 : 2, dyn_3 : 3}

    DSE Search maps the dynamic field to a map collection column.

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