# Best Practices

## Attribute Configuration

**After scanning:**

* Review discovered attributes and verify inferred `DATA_PLATFORM_DATA_TYPE`
* Check for unexpected polymorphic version activations
* Review `HAS_EMBEDDED_CONTENT = TRUE` attributes (stringified JSON)

**Data type configuration:**

* Adjust `DATA_PLATFORM_DATA_TYPE_PRECISION` and `DATA_PLATFORM_DATA_TYPE_SCALE` for numeric types
* Set `DATA_PLATFORM_DATA_TYPE_DATETIMEFORMAT` when `USE_DATETIME_FORMAT = TRUE` for accurate parsing
* Use `ALIAS_NAME` for readable column names (overrides `POLYMORPHIC_ATTRIBUTE_NAME`)

**Null handling:**

* Set `NULL_VALUE_EXPRESSION` (only applies when `TRANSFORMATION_TYPE = 'No Transformation'`)
* Use `{attribute_name}` placeholder in expressions

**Transformations:**

* Use `TRANSFORMATION_EXPRESSION` when `TRANSFORMATION_TYPE = 'SQL Expression'`
* Document in `TRANSFORMATION_EXPRESSION_COMMENT`

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## Virtual Attributes

**Naming:** No spaces allowed in attribute names. Names appear in generated SQL as `CODE_GENERATED_COLUMN_NAME`.

**Transformation expressions:**

* Required field; must be valid SQL
* Can reference other attributes using `{attribute_name}` placeholder
* Automatically set to `INCLUDE_IN_CODE_GEN = TRUE`

**Semantic model integration:**

* Set `W_QUESTION_CATEGORY` for Cortex Analyst (values: `'dimensions'`, `'facts'`, `'filters'`, `'metrics'`, `'time_dimensions'`)
* Link to parent arrays when creating array-level virtual attributes

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## Polymorphic Versions

**Review versions:**

* Check all 7 versions for each attribute
* Monitor `VERSION_STATUS_DATE` to track schema evolution
* Set `INCLUDE_IN_CODE_GEN = FALSE` for versions you don't need

**Handling polymorphism:**

* Use transformation expressions to handle type variations
* Consider data quality implications when multiple versions are active
* Monitor newly activated versions after scans

**Version management:**

* Inactive versions are ready for activation (don't delete)
* Only `active` versions with `INCLUDE_IN_CODE_GEN = TRUE` generate columns

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## Performance

**Code generation:**

* Set `INCLUDE_IN_CODE_GEN = FALSE` for unused attributes
* Reduces Dynamic Table size and refresh time
* Child attributes only generated if `PARENT_INCLUDE_IN_CODE_GEN = TRUE`

**Clustering:**

* Set `ADD_TO_CLUSTER_BY = TRUE` for frequently queried attributes
* Improves query performance on large Dynamic Tables
* Balance with refresh performance impact

**Data type sizing:**

* Set appropriate `DATA_PLATFORM_DATA_TYPE_PRECISION` and `DATA_PLATFORM_DATA_TYPE_SCALE`
* Avoid over-sizing numeric types (wastes storage)