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Number of rows in the table

Verifies that the number of rows in a table does not exceed the minimum accepted count.

PROBLEM

America’s Health Rankings provides an analysis of national health on a state-by-state basis by evaluating a historical and comprehensive set of health, environmental and socioeconomic data to determine national health benchmarks and state rankings.

The platform analyzes more than 340 measures of behaviors, social and economic factors, physical environment and clinical care data. Data is based on public-use data sets, such as the U.S. Census and the Centers for Disease Control and Prevention’s Behavioral Risk Factor Surveillance System (BRFSS), the world’s largest, annual population-based telephone survey of over 400,000 people.

In this example, we will verify if the number of rows in a table does not exceed the minimum accepted count.

We want to verify that the number of rows in a table does not exceed the minimum accepted count.

SOLUTION

We will verify the data using profiling row_count table check. Our goal is to verify if the number of rows does not fall below setup thresholds.

In this example, we will set three minimum count thresholds levels for the check:

  • warning: 692
  • error: 381
  • fatal: 150

If you want to learn more about checks and threshold levels, please refer to the DQO concept section.

VALUE

If the number of rows falls below 692, a warning alert will be triggered.

Data structure

The following is a fragment of the bigquery-public-data.america_health_rankings.ahr dataset. Some columns were omitted for clarity.

edition report_type measure_name state_name subpopulation value
2021 2021 Health Disparities Able-Bodied Hawaii 87
2021 2021 Health Disparities Able-Bodied Kentucky 79
2021 2021 Health Disparities Able-Bodied Maryland 87
2021 2021 Health Disparities Able-Bodied New Jersey 87
2021 2021 Health Disparities Able-Bodied Utah 88
2021 2021 Health Disparities Able-Bodied West Virginia 77
2021 2021 Health Disparities Able-Bodied Arkansas Female 78
2021 2021 Health Disparities Able-Bodied California Female 87
2021 2021 Health Disparities Able-Bodied Colorado Female 87

YAML configuration file

The YAML configuration file stores both the table details and checks configurations.

In this example, we have set three minimum count thresholds levels for the check:

  • warning: 692
  • error: 381
  • fatal: 150

The highlighted fragments in the YAML file below represent the segment where the profiling row_count check is configured.

If you want to learn more about checks and threshold levels, please refer to the DQO concept section.

apiVersion: dqo/v1
kind: table
spec:
  incremental_time_window:
    daily_partitioning_recent_days: 7
    monthly_partitioning_recent_months: 1
  profiling_checks:
    volume:
      profile_row_count:
        comments:
        - date: 2023-05-05T12:19:34.814+00:00
          comment_by: user
          comment: "\"In this example, we verify if the number of rows in a table\
            \ does not exceed the minimum accepted count.\""
        warning:
          min_count: 692
        error:
          min_count: 381
        fatal:
          min_count: 150
  columns:
    edition:
      type_snapshot:
        column_type: INT64
        nullable: true
    report_type:
      type_snapshot:
        column_type: STRING
        nullable: true
    measure_name:
      type_snapshot:
        column_type: STRING
        nullable: true
    state_name:
      type_snapshot:
        column_type: STRING
        nullable: true

Running the checks in the example and evaluating the results using the graphical interface

The detailed explanation of how to run the example is described here.

To execute the check prepared in the example using the graphical interface:

Navigating to a list of checks

  1. Go to the Profiling section.

  2. Select the table or column mentioned in the example description from the tree view on the left.

  3. Select the Advanced Profiling tab.

  4. Run the enabled check using the Run check button. Run check

  5. Review the results by opening the Check details button. Check details

  6. You should see the results as the one below. The actual value of rows in this example is 18155, which is above the minimum threshold level set in the warning (692). The check gives a valid result (notice the green square on the left of the name of the check).

    Row-count check results

  7. After executing the checks, synchronize the results with your DQO cloud account sing the Synchronize button located in the upper right corner of the graphical interface.

  8. To review the results on the data quality dashboards go to the Data Quality Dashboards section and select the dashboard from the tree view on the left. Below you can see the results displayed on the Issues dashboard showing results by check, number of issues per connection, and number of issues per table.

    Row-count results on Issues dashboard

Running the checks in the example and evaluating the results using DQO Shell

The detailed explanation of how to run the example is described here.

To execute the check prepared in the example, run the following command in DQO Shell:

check run
You should see the results as the one below. The number of rows is above 692 and the check gives valid result. 
Check evaluation summary per table:
+---------------+---------------------------+------+--------------+-------------+--------+------+------------+----------------+
|Connection     |Table                      |Checks|Sensor results|Valid results|Warnings|Errors|Fatal errors|Execution errors|
+---------------+---------------------------+------+--------------+-------------+--------+------+------------+----------------+
|table_row_count|america_health_rankings.ahr|1     |1             |1            |0       |0     |0           |0               |
+---------------+---------------------------+------+--------------+-------------+--------+------+------------+----------------+
For a more detailed insight of how the check is run, you can initiate the check in debug mode by executing the following command:

check run --mode=debug

In the debug mode you can view the SQL query (sensor) executed in the check.

**************************************************
Executing SQL on connection table_row_count (bigquery)
SQL to be executed on the connection:
SELECT
    COUNT(*) AS actual_value,
    CURRENT_TIMESTAMP() AS time_period,
    TIMESTAMP(CURRENT_TIMESTAMP()) AS time_period_utc
FROM `bigquery-public-data`.`america_health_rankings`.`ahr` AS analyzed_table
GROUP BY time_period, time_period_utc
ORDER BY time_period, time_period_utc
**************************************************
You can also see the results returned by the sensor. The actual value of rows in this example is 18155, which is above the minimum threshold level set in the warning (692). 
**************************************************
Finished executing a sensor for a check row_count on the table america_health_rankings.ahr using a sensor definition table/volume/row_count, sensor result count: 1

Results returned by the sensor:
+------------+------------------------+------------------------+
|actual_value|time_period             |time_period_utc         |
+------------+------------------------+------------------------+
|18155       |2023-05-05T12:29:22.192Z|2023-05-05T12:29:22.192Z|
+------------+------------------------+------------------------+
**************************************************