> ## Documentation Index
> Fetch the complete documentation index at: https://docs.dqlabs.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Overview

> What Distribution metrics are in Prizm — capture the character- and value-level composition of a column, including nullness, whitespace, and sign.

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## What is a Distribution metric?

Distribution metrics capture the **character-level and value-level composition of a column** — nullness, character types, whitespace, distinct values, and numeric sign. They reveal structural quality issues that aggregate counts and row-level checks miss entirely.

**Type:** Configurable — Distribution metrics are part of the Structural (Advanced) profile. They are enabled per column by mapping the asset and attribute through the Configure Structural Metrics panel.

Distribution metrics answer the question: *What does the content of each column actually look like?*

### Metrics

| Metric            | Level     | Description                                                                               |
| ----------------- | --------- | ----------------------------------------------------------------------------------------- |
| Null              | Attribute | Count of null values in the column                                                        |
| Null Percentage   | Attribute | Percentage of values that are null                                                        |
| Non-Empty         | Attribute | Count of values that are non-null and non-empty                                           |
| Blank Percentage  | Attribute | Percentage of values that are blank (null, empty string, or whitespace-only)              |
| Empty             | Attribute | Count of values that are empty strings                                                    |
| Distinct          | Attribute | Count of unique non-null values — tracks column cardinality over time                     |
| Repeating         | Attribute | Count of values that appear more than once — complements Distinct for uniqueness analysis |
| Zero Value        | Attribute | Count of numeric values equal to zero                                                     |
| Positive          | Attribute | Count of values greater than zero                                                         |
| Negative          | Attribute | Count of values less than zero                                                            |
| Special Character | Attribute | Count of values containing special (non-alphanumeric) characters                          |
| Alphabet          | Attribute | Count of values containing only alphabetic characters                                     |
| Alpha Numeric     | Attribute | Count of values containing both letters and digits                                        |
| Digit             | Attribute | Count of values containing only numeric digits                                            |
| Character         | Attribute | Count of values containing any character (non-null, non-empty)                            |
| Whitespace        | Attribute | Count of values containing whitespace characters                                          |
| Space             | Attribute | Count of values consisting entirely of space characters                                   |
| Trailing Space    | Attribute | Count of values with one or more trailing space characters                                |
| Inner Space       | Attribute | Count of values with internal (non-leading, non-trailing) spaces                          |
| Outer Space       | Attribute | Count of values with leading or trailing spaces                                           |
| Leading Space     | Attribute | Count of values with one or more leading space characters                                 |

### How distribution monitoring works

On each profiling run, Prizm profiles every configured attribute and records the distribution snapshot. Anomaly detection compares each metric against its historical baseline. For null-related metrics, absolute thresholds can also be configured — for example, "alert if Null Percentage exceeds 5%."

### Example use cases

**Email column validation:** A `customer_email` column that should always contain a valid email address begins showing an increase in Special Character counts and a decrease in Alpha Numeric counts after a source system migration. Prizm alerts on both metrics, pointing to a format change in how emails are stored — discovered before the CRM team notices bounce rates increasing.

**PII completeness monitoring:** A `tax_id` column is legally required for all corporate accounts. Prizm monitors Null Percentage on the column with a threshold of 0%. Any null in the column immediately triggers an alert, allowing the compliance team to trace the record back to the source and remediate.

<Note>
  Distribution metrics run at the Attribute (column) level. They must be explicitly enabled for each column via the Configure Structural Metrics panel — they do not activate automatically on all columns.
</Note>

<Card title="Configure" icon="sliders" href="/architecture/metrics/distribution/configure">
  Enable Distribution metrics per column, set thresholds, and configure alerts.
</Card>