We recommend that you choose nighttime or off-peak hours if you want to work with a large amount of data collectively through API or other programs.
If you add, update, or delete a lot of records in bulk, it may take some time until the changes are reflected on the results of a search or filter.
Bulk changes are gradually reflected in the search results.

For the deletion of multiple records, deleting records in bulk rather than deleting them individually may cause the changes to be reflected in search results in a shorter period of time.