Patent ID: 7373340

Claim:
A computer implemented method to store data sets in and to retrieve data sets from a data storage system in a restricted number of data sets and sorted by a data attribute of the data set, comprising: storing data sets each including one or more attributes in a plurality of binary tree structures ( 1 ), each of said binary tree structures ( 1 ) comprising nodes ( 2 ) and representing the entity of one of the data attributes of the data sets in a sorted manner, receiving a query to search and to return data sets according to query conditions in said restricted number of data sets and sorted by a sort attribute, accessing the binary tree structure ( 1 ) of said sort attribute, serially traversing the nodes ( 2 ) of said binary tree structure ( 1 ) according to the sort attribute, at each node ( 2 ) checking whether the data set associated to said node meets the query conditions and, if this is true, then returning said data set, wherein, in case that the sort attribute is part of the query conditions, only said nodes ( 2 ) of the binary tree structure ( 1 ) representing the sort attribute are accessed which meet the query condition, and terminating said traversing when said restricted number of data sets is reached.