How Min Partition Size Checks Work

Definition

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

Overview

The Min Partition Size rule sets a lower bound on the number of records the platform loads from a single partition. After each partition is loaded, its record count is compared against the configured Minimum partition size, and a partition that falls short is reported.

Because the rule looks at the load rather than the data, it takes no field, no filter clause, and no coverage threshold. A partition either clears the floor or it does not.

Typical use cases:

• Ensure partitions contain enough data to be meaningful.
• Detect incomplete data loads.
• Validate minimum batch processing thresholds.

Field Scope

None: The rule takes no field. It counts the records in each loaded partition, so the check is attached to the container itself and the form shows no field picker.

Anomaly Types

Evaluation Flow

Every Min Partition Size check follows the same three-step evaluation flow:

1. Load the partition. The Scan reads one partition of the container: a file, or the slice of a table the read strategy selected.
2. Count its records. The platform uses the measured record count for that partition. When no measured count is available, it falls back to the number of rows in the loaded data.
3. Compare it against the threshold. The partition passes when its count is at or above Minimum partition size. A partition below the threshold produces a Shape Anomaly naming the partition.

What Counts as a Partition

A partition is one unit of data the platform loads during a Scan. What that means depends on the container:

• For a file container, each file loaded from the folder is a partition.
• For a table, the partition is the slice the Scan loads: the whole table on a Full scan, or the incremental slice on an Incremental scan.

The check runs once per loaded partition, so a container that loads several partitions in one Scan is evaluated several times, and each failing partition produces its own anomaly.

The Rule Evaluates the Load, Not the Values

Min Partition Size never reads a column. It compares a record count against a number, which is why the form shows no field picker, no filter clause, and no coverage slider: there are no rows to scope or to tolerate.

That also means the rule cannot tell you which records are missing or extra. It tells you the partition is the wrong size. Pair it with a value-level check when you also need to know what is wrong inside it.

The Threshold Applies Per Partition, Not Per Container

A container that loads ten partitions in one Scan is evaluated ten times against the same threshold. The number you set is the size of one partition, not the total for the Scan. If you want to bound the whole container instead, use a Volumetric check, which tracks the container's row count over time.

No Filter Clause

Min Partition Size takes no filter clause. The rule counts the records in a loaded partition, and a row filter would change the count it is meant to measure, so the form shows no Filter Clause field and the API ignores the filter value.

Coverage

Min Partition Size does not use a coverage threshold. The coverage field on the API payload is ignored.

See Also