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import os
import pytest
import shlex
from subprocess import check_call

from tests.common.test_vector import ImpalaTestDimension
from tests.common.impala_test_suite import ImpalaTestSuite
from tests.util.filesystem_utils import get_fs_path

MT_DOP_VALUES = [0, 1, 2, 8]

class TestParquetStats(ImpalaTestSuite):
  """
  This suite tests runtime optimizations based on Parquet statistics.
  """

  @classmethod
  def get_workload(cls):
    return 'functional-query'

  @classmethod
  def add_test_dimensions(cls):
    super(TestParquetStats, cls).add_test_dimensions()
    cls.ImpalaTestMatrix.add_dimension(ImpalaTestDimension('mt_dop', *MT_DOP_VALUES))
    cls.ImpalaTestMatrix.add_constraint(
        lambda v: v.get_value('table_format').file_format == 'parquet')

  def test_parquet_stats(self, vector, unique_database):
    # The test makes assumptions about the number of row groups that are processed and
    # skipped inside a fragment, so we ensure that the tests run in a single fragment.
    vector.get_value('exec_option')['num_nodes'] = 1
    self.run_test_case('QueryTest/parquet-stats', vector, use_db=unique_database)

  def test_deprecated_stats(self, vector, unique_database):
    """Test that reading parquet files with statistics with deprecated 'min'/'max' fields
    works correctly. The statistics will be used for known-good types (boolean, integral,
    float) and will be ignored for all other types (string, decimal, timestamp)."""
    table_name = 'deprecated_stats'
    # We use CTAS instead of "create table like" to convert the partition columns into
    # normal table columns.
    self.client.execute('create table %s.%s stored as parquet as select * from '
                        'functional.alltypessmall limit 0' %
                        (unique_database, table_name))
    table_location = get_fs_path('/test-warehouse/%s.db/%s' %
                                 (unique_database, table_name))
    local_file = os.path.join(os.environ['IMPALA_HOME'],
                              'testdata/data/deprecated_statistics.parquet')
    assert os.path.isfile(local_file)
    check_call(['hdfs', 'dfs', '-copyFromLocal', local_file, table_location])
    self.client.execute('invalidate metadata %s.%s' % (unique_database, table_name))
    # The test makes assumptions about the number of row groups that are processed and
    # skipped inside a fragment, so we ensure that the tests run in a single fragment.
    vector.get_value('exec_option')['num_nodes'] = 1
    self.run_test_case('QueryTest/parquet-deprecated-stats', vector, unique_database)