I can't seem to find an explicit msdn article that mentions SharePoint Online can store up to 30,000,000 list items in a List. I saw that there is an article for the List View Threshold but it does not mention limits for the List itself. I assume it's similar to SharePoint 2013 which is 30,000,000 items.
We plan to use the list as a repository for "Custom Report"; an example would be when a search is performed, we 'track' the search and add an item to the list with data such as WHO performed the search, his / her username, etc.
One thing I am also concerned with this is querying the data, say, I only want items from August 2015. I can see that it is a fast growing list.
Is there a better way of doing what we want to do?