COALESCE is the function that returns the first value from a list that isn't empty. It takes a list of values as arguments and returns the first non-empty value. For example, COALESCE(NULL, '', 'Hello', 'World') returns 'Hello'. If all values are empty, it returns NULL. Reference: COALESCE

One possible reason why a new custom field is not available in the data stream is that the Salesforce Integration User, which is used to connect to the CRM source, does not have "Read" permissions on that field2. To fix this issue, the administrator needs to grant the appropriate permissions to the Integration User profile or permission set.

The recommended order of processes for updating data in Data Cloud is as follows6:
Refresh Data Stream: This process updates the data from the source, such as Amazon S3, into Data Cloud.
Identity Resolution: This process runs the rulesets that link together multiple records of an individual into a unified profile.
Calculated Insight: This process calculates additional attributes based on existing data, such as lifetime value or churn risk.

Text Measures and Date Time Measures cannot be used in Segmentation. Segmentation is the process of creating filtered audience segments based on calculated insights. Calculated insights are metrics that define and calculate multidimensional measures on your data. Only Numeric Measures can be used as calculated insights, because they can be aggregated using functions such as SUM, AVG, MIN, MAX, or COUNT. Text Measures and Date Time Measures are not types of measures, but types of dimensions. Dimensions are fields that can be used to group or filter data, but not to perform calculations. Reference: Measures and Dimensions

The app details page shows the status of the app, such as active, inactive, or error. The tenant specific endpoint is a unique URL that is generated for each app and used to send data to Data Cloud from the web or mobile SDK. Reference: https://help.salesforce.com/s/articleView?id=sf.c360_a_web_mobile_app_connector.htm&type=5