Profiling

Data Profiling

Before diving into data analytics within a Data Catalog, it's critical to ensure your data has been properly profiled. Data profiling is not just a step but a prerequisite. Without a valid data profile, proceeding to data identification tasks is premature.

What is Data Profiling?

Data profiling involves a detailed examination of your dataset, focusing on specific data objects. During this process, you collect valuable statistics and summaries that provide insights into the nature of your data. The beauty of data profiling is its immediacy. As soon as data from a column, table, or schema is processed, the results are ready for review.

When a data source schema is initially ingested, you're limited to the database metadata. Data profiling enriches this by uncovering additional layers of information, making it an indispensable tool in the data analyst's toolkit.

Click the Data Profiling tile.

The Profiling page opens with the following additional options to configure data profiling.

Data Catalog supports profiling of a wide range of file-based data assets. The following table highlights the major categories and commonly used file types that share a unified profiling interface and results:

Data Profiling

In the Data Profiling process, Data Catalog examines AW structured data within JDBC data sources and gathers statistics about the data. It profiles data using algorithms to compute detailed properties, including field-level data quality metrics, data statistics, and data patterns.

When configuring data profiling, it is considered a best practice to use the default settings as they are suitable for most situations. With the default settings, the data profiling is limited to 500,000 rows.

Field

Description

Extract samples

Extracts the sample data during profiling and displays it in the summary tab.

Skip Recent (days)

Skips profiling for recently profiled tables. For example, if the days field is set to 7, any table profiled within the last 7 days is skipped.

Sample Type

Specifies the sampling method for profiling:

Sample Clause: Profiles the sample data based on the percentage or rows*.
First N Rows: Profiles the first N rows of the data resource.
Every Nth Row: Profiles every Nth row of the data resource.
Filter: Profiles data using a custom SQL WHERE clause, that helps to target specific subsets of data based on user-defined conditions.
- Where Clause#: SQL condition used for data selection when Filter is enabled. For example, country = 'USA'.
Clear: Resets the sampling configuration.

Split Job by Columns

Splits profiling jobs by columns, allowing parallel processing for wide tables.

Columns Per Job

When splitting by columns is enabled, specifies the number of columns included in each job.

Number of Tables Per Job

Specifies the number of tables included in a single profiling job.

Persist Threads

Defines the number of threads used for persisting profiling results to improve performance.

Persist File Threads

Sets the number of threads for persisting profiling data into files for large datasets.

Profile Threads

Indicates the number of threads allocated for profiling tasks, enabling parallel task execution.

The Sample Clause > Rows option is supported only for the Microsoft SQL and Snowflake data sources.

Enable: Extract Samples.
Set Sample Type: Percentage (30)

Keep the other default values ..

The Profiling will use Reservoir Sampling 30% of total records.

Click: 'Start'.

You can You can view the status of the Profiling process on the Workers page.

The dataset has now been scanned which returns the metadata properties along with some additional details.

Next stage: Explore the data to confirm the details.

Profiled Data

If you select a data source, you can view available items like schema for structured data and folders for file systems. In addition, you can also get the number of tables and columns, including associated tags. For schemas, you can get additional information like row count and the last profiled date and time.

Navigate to: Person. schema
Enter a description:

Schema

Description

Sensitivity

HumanResources

Contains tables related to employee information, departmental structures, payroll history, and job candidates for the fictional company's workforce management.

HIGH

Person

Stores information about human beings involved with Adventure Works including employees, customer contacts, and vendor contacts, along with their addresses, phone numbers, and email information.

HIGH

Production

Manages data related to products sold or used in manufacturing, including product details, bills of materials, work orders, and manufacturing processes.

MEDIUM

Purchasing

Handles vendor relationships, purchase orders, product sourcing, and supplier management for the company's procurement operations.

MEDIUM

Sales

Contains all sales-related data including customer information, sales orders, sales territories, sales representatives, credit cards, and revenue tracking.

HIGH

Data Discovery - also determined the level of Sensitivity. Set the level for each schema.
Data Discovery - also calculated a Confidence Score - set the number of stars for each Schema.

System Information: highlights when the Schema was last scanned.

Properties: 15 columns

Click: Details tab.

Information on the number of Rows and Data Profiling date have been calculated.

Let's dig a bit deeper and see what other stats are available.

Expand the Person schema > Person table.
Select: Summary tab.
Enter a description (only 70 tables left):

The Person.Person table stores fundamental personal information for all human beings involved with Adventure Works, including employees, customer contacts, and vendor contacts, serving as the central repository for individual identity data such as names, titles, and demographic information that links to other business entities throughout the database.