ArcGIS Pro 3.4 API Reference Guide
ArcGIS.Core.Data.DDL Namespace / SchemaBuilder Class / Create Method / Create(IndexDescription) Method
Indicates the ArcGIS.Core.Data.Index to be created.
Example Version

Create(IndexDescription) Method
Enqueue the create operation on the object referred to by the IndexDescription. This method must be called on the MCT. Use QueuedTask.Run.
Syntax
public void Create( 
   IndexDescription indexDescription
)

Parameters

indexDescription
Indicates the ArcGIS.Core.Data.Index to be created.
Exceptions
ExceptionDescription
indexDescription is null.
Memory ArcGIS.Core.Data.Geodatabase does not support indexes.
Attribute indexes must be ascending on KnowledgeGraphs
User defined spatial indexes cannot be added to a knowledge graph
This method or property must be called within the lambda passed to QueuedTask.Run.
Remarks
Attribute indexes being added to a knowledge graph dataset must be ascending or a System.InvalidOperationException will be thrown.
User-defined spatial indexes cannot be added to a knowledge graph dataset. The system automatically creates the spatial index(es) when the dataset is created.
Example
Creating a table with index from scratch
public void CreatingTableWithIndex(SchemaBuilder schemaBuilder)
{
    FieldDescription nameFieldDescription = FieldDescription.CreateStringField("Name", 50);
    FieldDescription addressFieldDescription = FieldDescription.CreateStringField("Address", 200);

    // Creating a feature class, 'Buildings' with two fields
    TableDescription tableDescription = new TableDescription("Buildings", new List<FieldDescription>() { nameFieldDescription, addressFieldDescription });

    // Enqueue DDL operation to create a table
    TableToken tableToken = schemaBuilder.Create(tableDescription);

    // Creating an attribute index named as 'Idx'
    AttributeIndexDescription attributeIndexDescription = new AttributeIndexDescription("Idx", new TableDescription(tableToken),
      new List<string> { nameFieldDescription.Name, addressFieldDescription.Name });

    // Enqueue DDL operation to create an attribute index
    schemaBuilder.Create(attributeIndexDescription);

    // Execute build indexes operation
    bool isBuildSuccess = schemaBuilder.Build();
}
Adding indexes in pre-existing dataset
public void AddingIndexes(SchemaBuilder schemaBuilder, FeatureClassDefinition featureClassDefinition)
{
    // Field names to add in the attribute index
    string fieldName = featureClassDefinition.GetFields().First(f => f.AliasName.Contains("Name")).Name;
    string fieldAddress = featureClassDefinition.GetFields().First(f => f.AliasName.Contains("Address")).Name;

    // Creating an attribute index with index name 'Idx' and two participating fields' name
    AttributeIndexDescription attributeIndexDescription = new AttributeIndexDescription("Idx", new TableDescription(featureClassDefinition), new List<string> { fieldName, fieldAddress });

    // Enqueue DDL operation for an attribute index creation 
    schemaBuilder.Create(attributeIndexDescription);

    // Creating the spatial index 
    SpatialIndexDescription spatialIndexDescription = new SpatialIndexDescription(new FeatureClassDescription(featureClassDefinition));

    // Enqueue DDL operation for the spatial index creation
    schemaBuilder.Create(spatialIndexDescription);

    // Execute build indexes operation
    bool isBuildSuccess = schemaBuilder.Build();

    if (!isBuildSuccess)
    {
        IReadOnlyList<string> errors = schemaBuilder.ErrorMessages;
        // Iterate and handle errors 
    }
}
Create Attribute Indexes on KG Schemas with SchemaBuilder
await QueuedTask.Run(() =>
{
  using (var kg = GetKnowledgeGraph())
  {
    if (kg == null)
      return;

    var entity_name = "PhoneCall";

    //indexes are managed on the GDB objects...
    var entity_table_def = kg.GetDefinition<TableDefinition>(entity_name);
    var entity_table_desc = new TableDescription(entity_table_def);


    var entity_table_flds = entity_table_def.GetFields();
    AttributeIndexDescription attr_index1 = null;
    AttributeIndexDescription attr_index2 = null;
    foreach (var fld in entity_table_flds)
    {
      //index the first string field
      if (fld.FieldType == FieldType.String && attr_index1 == null)
      {
        if (fld.Name == "ESRI__ID")//special case
          continue;
        //Index _must_ be ascending for KG
        attr_index1 = new AttributeIndexDescription(
          "Index1", entity_table_desc, new List<string> { fld.Name })
        {
          IsAscending = true
        };
      }
      //index the first numeric field (if there is one)
      if ((fld.FieldType == FieldType.BigInteger ||
           fld.FieldType == FieldType.Integer ||
           fld.FieldType == FieldType.Single ||
           fld.FieldType == FieldType.SmallInteger ||
           fld.FieldType == FieldType.Double) && attr_index2 == null)
      {
        attr_index2 = new AttributeIndexDescription(
          "Index2", entity_table_desc, new List<string> { fld.Name })
        {
          IsAscending = true,
          IsUnique = true //optional - unique if all values are to be unique in the index
        };
      }
      if (attr_index1 != null && attr_index2 != null) break;
    }

    if (attr_index1 == null && attr_index2 == null)
      return; //nothing to index

    //Run the schema builder
    try
    {
      SchemaBuilder sb = new(kg);
      if (attr_index1 != null)
        sb.Create(attr_index1);
      if (attr_index2 != null)
        sb.Create(attr_index2);
      if (!kg.ApplySchemaEdits(sb))
      {
        var err_msg = string.Join(",", sb.ErrorMessages.ToArray());
        System.Diagnostics.Debug.WriteLine($"Create index error: {err_msg}");
      }
    }
    catch (Exception ex)
    {
      System.Diagnostics.Debug.WriteLine(ex.ToString());
    }
  }
});
Requirements

Target Platforms: Windows 11, Windows 10

ArcGIS Pro version: 3.1 or higher.
See Also