# Arrays

## Overview

Arrays metadata configures how array attributes are handled in code generation, including table creation, relationships, and aliases. Only applicable to semi-structured data sources with array attributes.

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## Array Configuration Fields

**Include In Code Gen (`INCLUDE_IN_CODE_GEN`)**

* Boolean for including array in SQL code generation
* **Editable** - `TRUE` = Dynamic Table created, `FALSE` = excluded
* Child attributes only generated if parent array is included (`PARENT_INCLUDE_IN_CODE_GEN = TRUE`)

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**Create Object Name Alias Name (`CREATE_OBJECT_NAME_ALIAS_NAME`)**

* Custom alias for materialized Dynamic Table created for this array
* **Editable** - Overrides default name (typically `{array_name}_array_object`)
* Example: `orders` → default `orders_array_object`, custom `order_items`

**Semantic Layer Alias Name (`SEMANTIC_LAYER_ALIAS_NAME`)**

* Custom alias for array in semantic layer views
* **Editable** - Overrides materialized table name in views

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**Relationship Name (`RELATIONSHIP_NAME`)**

* Name of relationship for this array
* **Editable** - Used for documentation

**Relationship Description (`RELATIONSHIP_DESCRIPTION`)**

* Description of relationship
* **Editable** - Documents business logic

**Relationship Type (`RELATIONSHIP_TYPE`)**

* Type of relationship between array and parent
* **Editable** - Values: `'many_to_one'` (most common), `'one_to_one'`

**Join Type (`JOIN_TYPE`)**

* Type of join used in relationship
* **Editable** - Values: `'left_outer'` (include all parents), `'inner'` (only parents with array data)

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**Array Security Row Level Policy Name Semantic Layer (`ARRAY_SECURITY_ROW_LEVEL_POLICY_NAME_SEMANTIC_LAYER`)**

* Name of row-level security policy for array tables in semantic layer views
* **Editable** - Applied to array tables in generated views
* Requires Security Policy Integration product tier

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## Reference Fields (Read-only)

Shown for reference in Arrays section:

* `ATTRIBUTE_PATH` - Path to array attribute
* `POLYMORPHIC_ATTRIBUTE_NAME` - Version name
* `ARRAY_TYPE` - `'object'`, `'primitive'`, or `'primitive,object'`
* `SOURCE_DATA_TYPE` - Always `'array'` for array attributes
* `PARENT_ARRAY` - Parent array if nested

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## Array Table Generation

When `INCLUDE_IN_CODE_GEN = TRUE`:

1. **Root Table** - Contains parent record data
2. **Array Table** - Separate Dynamic Table for array contents
   * Named using `CREATE_OBJECT_NAME_ALIAS_NAME` or default
   * Contains all attributes from array elements
   * Includes foreign key columns (configured in Foreign Keys section)
3. **Relationship** - Foreign key relationship links array table to root table
   * Based on `RELATIONSHIP_TYPE` and `JOIN_TYPE`

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## Array Types

**Object Arrays (`ARRAY_TYPE = 'object'`):**

* Each element is an object with attributes
* Creates separate table with all element attributes
* Supports foreign key relationships
* Configure: `INCLUDE_IN_CODE_GEN = TRUE`, relationship type/join type, foreign keys

**Primitive Arrays (`ARRAY_TYPE = 'primitive'`):**

* Elements are simple values (strings, numbers, booleans)
* May be stored as VARIANT or ARRAY types in root table
* May be flattened into separate table depending on configuration

**Polymorphic Arrays (`ARRAY_TYPE = 'primitive,object'`):**

* Contains both objects and primitives
* Both `array_primitive` and `array_object` versions may be active
* Configure each version separately

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## Best Practices

**Naming:**

* Use descriptive, business-friendly names for `CREATE_OBJECT_NAME_ALIAS_NAME`
* Use clear relationship names in `RELATIONSHIP_NAME`

**Relationship configuration:**

* Many-to-One: Standard array relationships (most common)
* One-to-One: Optional single-element arrays (less common)
* Left Outer: Include all parents (most common)
* Inner: Only parents with array data

**Performance:**

* Set `INCLUDE_IN_CODE_GEN = FALSE` for unused arrays
* Reduces table count and improves refresh performance
* Large arrays may impact performance; monitor Dynamic Table refresh times

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## Common Scenarios

**Configuring order items array:**

1. Set `INCLUDE_IN_CODE_GEN = TRUE`
2. Set `CREATE_OBJECT_NAME_ALIAS_NAME = 'order_items'`
3. Set `RELATIONSHIP_NAME = 'Orders to Items'` (optional)
4. Set `RELATIONSHIP_TYPE = 'many_to_one'`
5. Set `JOIN_TYPE = 'left_outer'`
6. Configure foreign keys in Foreign Keys section

**Excluding unused arrays:**

* Set `INCLUDE_IN_CODE_GEN = FALSE`
* Array table won't be generated; reduces schema complexity and improves performance

**Nested arrays:**

* Configure parent array first
* Configure nested array separately
* `PARENT_ARRAY` reference set automatically
* Configure foreign keys for each level

**Array security:**

* Set `ARRAY_SECURITY_ROW_LEVEL_POLICY_NAME_SEMANTIC_LAYER`
* Create policy in Snowflake
* Policy applied to array table in views


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