When inputting new data for a private version in a story in SAP Analytics Cloud, it is necessary to "Publish" the data to ensure it is added to the model. Publishing the private version commits the changes to the underlying model, making the new data visible and accessible to other users according to their permissions. This step is crucial for ensuring that the updated data is incorporated into the shared model for further analysis and decision-making.
Reference:
SAP Analytics Cloud Help Documentation: Private Versions and Publishing SAP Analytics Cloud User Guide: Working with Private Versions in Stories

In a planning data model in SAP Analytics Cloud, the Date and Version dimensions are included by default. The Date dimension is essential for time-based planning and analysis, while the Version dimension allows for the creation and management of different data scenarios, such as budget, forecast, and actuals. These dimensions provide a foundational structure for planning activities within the model.
Reference:
SAP Analytics Cloud Help Documentation: Planning Data Model Basics
SAP Analytics Cloud User Guide: Understanding Default Dimensions in Planning Models

SAP Analytics Cloud can establish a live connection with various source systems, including SAP Datasphere. This allows for real-time data access and analysis without the need to replicate data into the cloud, which is beneficial for scenarios where data privacy and security are paramount.
Reference:
SAP Analytics Cloud Connection Guide1
SAC Live and Import Connection Overview2
SAP Analytics Cloud: Expand Live Data Source Options3
Live connection in SAP Analytics Cloud: advantages and challenges4
Explaining Where the Data Comes From - SAP Learning5

To combine two dimensions, Firstname and Lastname, into a single dimension displaying as Lastname, Firstname in a live data model, you should create a calculated dimension in the data model. This calculated dimension will concatenate the two fields into one, according to the specified format. This approach allows for the creation of a new dimension that can be used across various reports and analyses within the model, maintaining the integrity of the original dimensions.
Reference:
SAP Analytics Cloud Help Documentation: Creating Calculated Dimensions
SAP Analytics Cloud User Guide: Data Modeling Best Practices