public EnumSet<IndexingType> getFieldIndexingTypes(Symbol fieldDefinition) {
        FieldIndexEntry entry = database.get(fieldDefinition);

        if (entry == null) return EnumSet.noneOf(IndexingType.class);

        return EnumSet.copyOf(entry.indexingTypes);
    }
FieldIndex
For storing metadata about fields.
It is owned by a SchemaIndex, so there is a one-to-one correspondence
integration/schema-language-server/language-server/src/main/java/ai/vespa/schemals/index/FieldIndex.java