Min Partition Size

Definition

Asserts the minimum number of records that should be loaded from each file or table partition.

In-Depth Overview

When working with large datasets that are often partitioned for better performance and scalability, ensuring a certain minimum number of records from each partition becomes crucial. This could be to ensure that each partition is well-represented in the analysis, to maintain data consistency or even to verify that data ingestion or migration processes are functioning properly.

The Min Partition Size rule allows users to set a threshold ensuring that each partition has loaded at least the specified minimum number of records.

General Properties

Details

Name	Supported
Filter Allows the targeting of specific data based on conditions
Coverage Customization Allows adjusting the percentage of records that must meet the rule's conditions

Specific Properties

Sets the required minimum record count for each data partition

Name	Description
Minimum partition size	Specifies the minimum number of records that should be loaded from each partition

Anomaly Types

Type	Supported
Record Flag inconsistencies at the row level
Shape Flag inconsistencies in the overall patterns and distributions of a field

Example

Objective: Ensure that each partition of the LINEITEM table has at least 1000 records.

Sample Data for Partition P3

Row Number	L_ITEM
1	Data
2	Data
...	...
900	Data

The sample data above does not satisfy the rule because it contains only 900 records, which is less than the required minimum of 1000 records.

FlowchartSQL

graph TD
A[Start] --> B[Retrieve Number of Records for Each Partition]
B --> C{Does Partition have >= 1000 records?}
C -->|Yes| D[Move to Next Partition/End]
C -->|No| E[Mark as Anomalous]
E --> D

-- An illustrative SQL query demonstrating the rule applied to example dataset(s). 
select
    subset_name, -- or any column indicating the partition or subset
    count(*)
from lineitem 
group by subset_name
having count(*) < 1000;

Potential Violation Messages

Shape Anomaly

In LINEITEM, fewer than 900 records were loaded.

Last update: April 25, 2024