Deletes and updates

The access method uses the Contains function for index scans that search for leaf objects that must be deleted from the R-tree index after their associated row in the table is deleted.

The access method uses the Equal function to optimize the performance of updates to the R-tree index. When a row in a table is updated, any R-tree index on the table might also need to be updated. Updates usually mean deleting the old entry and inserting the new entry. First, however, the access method uses the Equal strategy function to check whether the new entry is different from the old entry. If they are both equal, the access method does not perform the update.