core/src/main/java/com/orientechnologies/orient/core/metadata/schema/OPropertyImpl.java
public OIndex<?> createIndex(final String iType) {
    acquireSchemaReadLock();
    try {
      return owner.createIndex(getFullName(), iType, globalRef.getName());
    } finally {
      releaseSchemaReadLock();
    }
  }
public OIndex<?> createIndex(final String iType) {
    acquireSchemaReadLock();
    try {
      return owner.createIndex(getFullName(), iType, globalRef.getName());
    } finally {
      releaseSchemaReadLock();
    }
  }
Creates an index on this property. Indexes speed up queries but slow down insert and update operations. For massive inserts we
suggest to remove the index, make the massive insert and recreate it.

@param iType

@return

@see {@link OClass#createIndex(String, OClass.INDEX_TYPE, String...)} instead.