Hi @管理 アカウント ,
AFAIK there is no threshold on working with list items using REST API. So to your questions:
- You will get all items that meet the filter in the list.
- 30 million is the threshold for the count of items in a list. So all 3 million items can be indexed as they don't exceed the 30 million limitation.
- Yes, it will work normally.
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