code: def test_native_engine_should_create_index(self):
      # Create table.
      query = """USE test_data_source {
              CREATE TABLE test_vector (idx INTEGER, dummy INTEGER, embedding vector(27))
          }"""
      execute_query_fetch_all(self.evadb, query)
  
      # Insert data.
      vector_list = [
          [0.0 for _ in range(9)]
          + [1.0 for _ in range(9)]
          + [2.0 for _ in range(9)],
          [1.0 for _ in range(9)]
          + [2.0 for _ in range(9)]
          + [3.0 for _ in range(9)],
          [2.0 for _ in range(9)]
          + [3.0 for _ in range(9)]
          + [4.0 for _ in range(9)],
          [3.0 for _ in range(9)]
          + [4.0 for _ in range(9)]
          + [5.0 for _ in range(9)],
          [4.0 for _ in range(9)]
          + [5.0 for _ in range(9)]
          + [6.0 for _ in range(9)],
      ]
      for idx, vector in enumerate(vector_list):
          query = f"""USE test_data_source {{
                  INSERT INTO test_vector (idx, dummy, embedding) VALUES ({idx}, {idx}, '{vector}')
              }}"""
          execute_query_fetch_all(self.evadb, query)
  
      # Create index.
      query = """CREATE INDEX test_index
              ON test_data_source.test_vector (embedding)
              USING PGVECTOR"""
      execute_query_fetch_all(self.evadb, query)
  
      # Check the existence of index.
      query = """USE test_data_source {
              SELECT indexname, indexdef FROM pg_indexes WHERE tablename = 'test_vector'
          }"""
      df = execute_query_fetch_all(self.evadb, query).frames
  
      self.assertEqual(len(df), 1)
      self.assertEqual(df["indexname"][0], "test_index")
      self.assertEqual(
          df["indexdef"][0],
          """CREATE INDEX test_index ON public.test_vector USING hnsw (embedding vector_l2_ops)""",
      )
  
      # Check the index scan plan.
      query = f"""SELECT idx, embedding FROM test_data_source.test_vector
              ORDER BY Similarity(DummyFeatureExtractor(Open('{self.img_path}')), embedding)
              LIMIT 1"""
      df = execute_query_fetch_all(
          self.evadb, f"EXPLAIN {query}"
      ).frames
      self.assertIn("VectorIndexScan", df[0][0])
  
      # Check results.
      df = execute_query_fetch_all(self.evadb, query).frames
      self.assertEqual(df["test_vector.idx"][0], 0)
      self.assertNotIn("test_vector.dummy", df.columns)
  
file_path: evadb/test/third_party_tests/test_native_similarity_index.py
imports: import unittest
  from test.util import create_sample_image, get_evadb_for_testing, load_functions_for_testing
  import pytest
  from evadb.server.command_handler import execute_query_fetch_all
label_desc: Use image node_id 3 for calling the CreateIndexTest obj's underlying member method code with example usage: obj.test_native_engine_should_create_index() without return types