A dataset is a type of data source that allows you to import data from files, such as Excel or CSV files. You can use datasets to create stories or blend data with models. However, datasets have some limitations, such as:

• They cannot be scheduled. You have to manually refresh the data in a dataset.
• They do not support column-based or property security. You cannot restrict access to certain columns or properties in a dataset.
• They do not support transformations. You cannot apply any transformations to the data in a dataset.
• They can overwrite imported data. You can choose to append or replace the data in a dataset when you import a new file.

Therefore, the correct answer is They cannot be scheduled and They do not support column-based or property security, as they are the limitations of datasets.

The model setting Optimize Story Building Performance prevents the automatic refresh of data during story design. This means that users can design stories without waiting for the data to load every time they make a change. Users can manually refresh the data when they want to see the updated results. The model setting does not affect the design experience, the parallel processing, or the story editing. Verified References: [SAP Analytics Cloud - Optimize Story Building Performance]

When you save a story as a template, you can use it as a starting point for creating new stories with the same layout and formatting. However, all the data from the original story is removed and replaced by placeholders for charts, tables, maps, input controls, and value driver trees. This way, you can easily add new data sources and models to the template without affecting the existing ones1. Custom formatting, such as story background, chart color palettes, fonts, and borders, is retained in the template2. Custom widgets, such as images, shapes, texts, and buttons, are also preserved in the template3. Standard widgets, such as charts, tables, maps, input controls, and value driver trees, are converted into empty placeholders that can be filled with new data3.

References:

1: Create and Use Story Templates 2: Story Templates in SAP Analytics Cloud 3: Building Stories from a Template