Set options to poll for data
Most monitor events work by polling the application for new data.
To launch the dialog for polling options, click Runs when: New data from the Options menu on any event polling card such as New Email for the Gmail connector.
For polling monitors, there are three options that can be chosen for when to run the Flow:
New Data (default)
Sets your Flow to run once for each new item. For example, if your Flow starts with a Salesforce - Monitor New event, then it will check Salesforce every 15 minutes (or another period of time you set it to) to see if new records have been added. If three new records were added since the last check, the Flow runs three separate times (once for each new record). If no new records were added, the Flow doesn't run at all.
No New Data
Allows you to trigger based on no records being found that match the event and criteria you specify. For example, you could set your Flow to check Salesforce every morning at 9am to see if there are new leads since the previous check. The No new data option tells the Flow to run when no new items is itself a trigger to start a Flow.
Your Flow will run every time it checks the application. For example, if you are checking every hour for new rows in a spreadsheet, the Flow will run exactly once every hour. Instead of getting data for a single row (as it does for the "New Data" option), a Flow gets a list that includes data for all of the new rows. If there were no new rows, the list is an empty list. This allows you the most flexibility to decide what actions to take, all in a single Flow. For example, you could take different actions based on the number of rows added that hour, including what to do if there are none.
Each Flow keeps track of when it last checked the application independent from other Flows. You can have multiple Flows looking at the same events: one that checks every 15 minutes for new items, another that runs if there are no new items during the previous 24 hours, and another that runs at the end of every week to gets all of the new items for that week.
Webhook monitors may also offer more than one option. For example, Smartsheet - Monitor New Rows notifies the Flow as soon as a smartsheet is saved with new rows. In the default monitor setting, the Flow will runs once for each new row. But you can also opt for list mode which runs the Flow just once and passes a list of all of the new rows.