Search indexes (Enterprise edition)

The pipeline search stage runs against search indexes, which only a database of the Firestore Enterprise edition has. A text index covers one or more string fields, and a geo index covers a geo point field. Declare them as composite indexes with .text() and .geo() on a field:

use firestore::*;
async fn example(db: FirestoreDb) -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
db.fluent()
    .indexes()
    .collection_group("restaurants")
    .composite(|i| {
        i.indexes([
            i.index([i.field("menu").text(), i.field("description").text()])
                .search_options(
                    FirestoreSearchIndexOptions::new().with_text_language("en".to_string()),
                ),
            i.index([i.field("location").geo()]),
        ])
    })
    .sync()
    .await?;
Ok(())
}

• A search index holds text and geo fields only. An index that mixes them with ordered, array or vector fields is rejected with InvalidParametersError at .plan()/.sync();
• A text search covers all the text fields of the index it uses, and Firestore offers no index that matches one field by name;
• .search_options(..) sets the options of a text index. text_language is the BCP 47 language tag the fields are indexed in, such as en; when it is left unset, Firestore detects each document’s language and lists the option as und, the code for an undetermined language. text_language_override_field_path names the field that holds a document’s own language, and Firestore reads language when it is unset. An index declared without options matches the index Firestore lists with those defaults;
• .geo_with(config) takes a FirestoreGeoIndexConfig that can leave GeoJSON points out of a geo index, which Firestore indexes by default;
• .all_descendants() on the index scopes it to a collection group, which a collection-group search needs;
• a search index is always built as FirestoreIndexDensity::SparseAny, see Density;
• a Standard edition database answers a search index with INVALID_ARGUMENT.