>> Performing storage and retrieval that uses the hashing technique with the external chaining method for collision resolution.
Isnt this just describing a hash table?
>> In order to prevent performance deterioration due to the presence of automatically expiring data items, a garbage collection technique is used that removes all expired records stored in the system in the external chain targeted by a probe into the data storage system.
So the software doesn't run slowly, we're going to do something special to get rid of those pesky expired records.
I believe, "removes all expired records stored in the system in the external chain targeted by a probe into the data storage system." is just preparing you for the description of what they're going to do, without actually saying anything.
>> Each insertion, retrieval, or deletion of a record is an occasion to search an entire linked-list chain of records for expired items and then remove them.
Whenever an action is taken on a record, remove expired records near the record targeted by the action.
>> Because an expired data item will not remain in the system long term if the system is frequently probed, it is useful for large information storage systems that are heavily used, require the fast access provided by hashing, and cannot be taken off-line for removal of expired data.
Expired items don't stay long. System doesn't have to be taken offline to remove expired items... Because they remove expired items after CRUD of a record takes place, I guess.
Surely I'm missing something here. Or is it just that silly that you can get a patent on something like this?