index-digest/indexdigest/test/linters/test_0031_low_cardinality_index.py at e94f538660690620e787c529a10be1cc97b7b0db · macbre/index-digest · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
from __future__ import print_function

from unittest import TestCase

from indexdigest.linters.linter_0031_low_cardinality_index import \
    check_low_cardinality_index, get_low_cardinality_indices
from indexdigest.test import DatabaseTestMixin


class TestLinter(TestCase, DatabaseTestMixin):

    def test_get_low_cardinality_indices(self):
        indices = list(get_low_cardinality_indices(self.connection))

        print(indices)

        assert len(indices) == 1
        assert indices[0][0] == '0020_big_table'
        assert indices[0][2]['INDEX_NAME'] == 'num_idx'
        assert indices[0][2]['COLUMN_NAME'] == 'num'
        assert indices[0][2]['CARDINALITY'] > 1
        assert indices[0][2]['CARDINALITY'] < 5

    def test_low_cardinality_index(self):
        reports = list(check_low_cardinality_index(self.connection))

        print(reports, reports[0].context)

        assert len(reports) == 1

        assert str(reports[0]) == '0020_big_table: "num_idx" index on "num" column ' \
                                  'has low cardinality, check if it is needed'
        assert reports[0].table_name == '0020_big_table'

        assert reports[0].context['column_name'] == 'num'
        assert reports[0].context['index_name'] == 'num_idx'
        assert isinstance(reports[0].context['index_cardinality'], int)
        assert int(reports[0].context['value_usage']) == 33