OneLake is a single, unified, logical data lake for your whole organization. Like OneDrive, OneLake comes automatically with every Microsoft Fabric tenant and is designed to be the single place for all your analytics data. OneLake brings customers:

• One data lake for the entire organization
• One copy of data for use with multiple analytical engines

What is OneLake?

• Before OneLake:
  • Customers used to make separate data lakes for different business groups.
  • Even though managing multiple lakes was extra work.
• OneLake Focus:
  • OneLake is all about making collaboration easier.
  • Each customer gets exactly one OneLake, ensuring a single place for data.
  • If a customer has Fabric, they always get OneLake automatically.
  • No extra effort is needed to set up or handle OneLake; it’s done automatically.

Overview on Fabric :

• Tenant Concept:
  • A tenant is a special feature of a SaaS (Software as a Service) service.
  • It helps to define the boundaries of a customer’s organization, which is managed by a tenant admin.
  • Data stored in OneLake (the centralized data lake) is automatically governed by default.
• Workspaces:
  • Within a tenant, you can create multiple workspaces.
  • Workspaces help different parts of the organization manage ownership and access to data.
  • Each workspace is linked to a specific region and is charged separately.
• Data Items:
  • In a workspace, you can create data items, which are like files.
  • All data in OneLake is accessed through these data items.
  • Just like how Office stores Word, Excel, and PowerPoint files in OneDrive, Fabric stores different types of data items in OneLake, such as lakehouses and warehouses.
  • Each data item can provide a customized experience for different users, such as Spark developers.

More details description on OneLake:

• OneLake Overview:
  • OneLake is a flexible storage system that works with any type of file, whether it’s structured or unstructured.
  • It’s based on Azure Data Lake Storage (ADLS) Gen2, which is a powerful storage service provided by Microsoft.
• Storage Format:
  • All data in OneLake is stored in a format called Delta Parquet, which is efficient and suitable for various types of data.
• Contributing Data:
  • Different teams can contribute to OneLake using various tools and methods.
  • For example, a data engineer might use Spark to load data into a lakehouse, while a SQL developer might use T-SQL to load data into a transactional data warehouse.
  • Regardless of how the data is loaded, it all ends up in the same data lake.
• Compatibility:
  • OneLake supports the same APIs and SDKs as ADLS Gen2, making it compatible with existing applications and services.
  • This includes compatibility with Azure Databricks, a popular big data processing platform.
• Organization Structure:
  • In OneLake, each workspace appears as a container, and different data items appear as folders within those containers.
  • This organization structure helps users manage and access their data effectively.

What is OneLake file explorer for Windows?

OneLake is the OneDrive for data. Just like OneDrive, you can easily explore OneLake data from Windows using the OneLake file explorer for Windows. You can navigate all your workspaces and data items, easily uploading, downloading, or modifying files just like you do in Office. The OneLake file explorer simplifies working with data lakes, allowing even nontechnical business users to use them. You must double-click on a file to download the data locally.

When you create, update, or delete a file via Windows File Explorer, it automatically syncs the changes to OneLake service. Updates to your item made outside of your File Explorer aren’t automatically synced. To pull these updates, you need to right-click on the item or subfolder in Windows File Explorer and select Sync from OneLake.

How to Installation OneLake file explorer for Windows?

OneLake file explorer currently supports Windows and has been validated on Windows 10 and 11.

To install:

1. Download the OneLake file explorer.
2. Double-click the file to start installing.The storage location on your PC for the placeholders and any downloaded content is \%USERPROFILE%\OneLake - Microsoft\.

Once you have installed and launched the application, you can now see your OneLake data in Windows File Explorer.

The following scenarios provide details for working with the OneLake file explorer.

• Starting and exiting OneLake file explorer
• Sync updates from OneLake
• Option to open workspaces and items on the web portal
• Offline support
• Create files or folders in OneLake file explorer
• Delete files or folders in OneLake file explorer
• Edit files
• Copying or moving files
• Support for large files and a large number of files
• OneLake shortcut support

OneLake file explorer icons

These OneLake file explorer icons appear in Windows File Explorer to indicate the sync state of the file or folder.

Icon	Icon description	Meaning
	Blue cloud icon	The file is only available online. Online-only files don’t take up space on your computer.
	Green tick	The file is downloaded to your local computer.
	Sync pending arrows	Sync is in progress. This icon may appear when you’re uploading files. If the sync pending arrows are persistent, then your file or folder may have an error syncing. You can find more information in the client-side logs on your local machine under %temp%\OneLake\Diagnostics\.