Implementation:Sdv dev SDV Get Cardinality Plot

Knowledge Sources	SDV SDMetrics Documentation
Domains	Visualization, Relational_Data
Last Updated	2026-02-14 00:00 GMT

Overview

Wrapper for SDMetrics cardinality visualization, comparing parent-child relationship distributions in multi-table data within SDV workflows.

Description

The get_cardinality_plot function creates a Plotly figure comparing the cardinality distribution (child rows per parent) between real and synthetic multi-table data.

Usage

Call with multi-table real and synthetic data, specifying the parent-child relationship.

Code Reference

Source Location

• Repository: SDV
• File: sdv/evaluation/multi_table.py
• Lines: L134-174

Signature

def get_cardinality_plot(
    real_data, synthetic_data, child_table_name, parent_table_name,
    child_foreign_key, metadata, plot_type='bar'
):
    """Plot cardinality distribution of a parent-child relationship.

    Args:
        real_data (dict): Real multi-table data.
        synthetic_data (dict): Synthetic multi-table data.
        child_table_name (str): Child table name.
        parent_table_name (str): Parent table name.
        child_foreign_key (str): Foreign key column in child table.
        metadata (Metadata): Multi-table metadata.
        plot_type (str): 'bar' or 'distplot'. Defaults to 'bar'.

    Returns:
        plotly.graph_objects.Figure: Cardinality comparison plot.
    """

Import

from sdv.evaluation.multi_table import get_cardinality_plot

I/O Contract

Inputs

Name	Type	Required	Description
real_data	dict[str, pd.DataFrame]	Yes	Real multi-table data
synthetic_data	dict[str, pd.DataFrame]	Yes	Synthetic multi-table data
child_table_name	str	Yes	Child table in the relationship
parent_table_name	str	Yes	Parent table in the relationship
child_foreign_key	str	Yes	Foreign key column in child table
metadata	Metadata	Yes	Multi-table metadata
plot_type	str	No	'bar' or 'distplot' (default: 'bar')

Outputs

Name	Type	Description
return value	plotly.graph_objects.Figure	Cardinality comparison plot

Usage Examples

from sdv.evaluation.multi_table import get_cardinality_plot

fig = get_cardinality_plot(
    real_data, synthetic_data,
    child_table_name='guests',
    parent_table_name='hotels',
    child_foreign_key='hotel_id',
    metadata=metadata,
)
fig.show()

Related Pages

Implements Principle

• Principle:Sdv_dev_SDV_Cardinality_Analysis

Requires Environment

• Environment:Sdv_dev_SDV_Python_Runtime