Method for securing access to a relation

A method for securing access to a set of data items using relations, a first relation of the relations comprising data items, the data items forming a partially ordered set in the first relation, wherein the insertion of a data item in the first relation is performed by a traversal method for traversing the first relation until reaching an insert position, the traversal method comprising at a currently traversed data item of the first relation:

• an order comparing step comprising comparing the data item to be inserted with the currently traversed data item resulting in a current comparison result, and a decision step comprising executing a decision logic for selecting one of a first and second sub-relations of the first relation based on the current comparison result in order to perform a next action, wherein the next action comprises a selection of a next data item to be traversed or to identify the insert position in the selected sub-relation, wherein each of the first and second sub-relations comprises zero or more data items succeeding and preceding the currently traversed data item respectively, the method comprising:
• predefining a reference data item;
• creating a relation and inserting a given data item of the set of data items into the relation;
• inserting each data item of the set of data items into the created relation using the traversal method, wherein the order comparing step comprises in case a comparison result of the currently traversed data item with the reference data item is different from a comparison result of the to be inserted data item with the reference data item inverting the decision logic, and using the inverted decision logic in the decision step;
• in response to receiving a data access request for searching a given data item in the created relation, traversing the created relation comprising:
• at a currently traversed data item of the created relation:
• comparing the given data item with the currently traversed data item resulting in a current first comparison result, comparing the given data item with the reference data item resulting in a second comparison result, comparing the currently traversed data item with the reference data item resulting in a third comparison result, based on the first comparison result deciding to select one of a first and second sub-relations of the created relation in order to perform a next action, and in case the second and third comparison results are different inverting the decision by selecting the other one of the first and second sub-relations in order to perform the next action, wherein the next action comprises a selection of a next data item to be traversed and/or to provide the currently traversed data item as the data item that satisfies the search request, wherein each of the first and second sub-relations comprises one or more data items succeeding and preceding the currently traversed data item respectively.

A method for building a relation, wherein the insertion of a data item in an existing relation is performed by a traversal method for traversing the exiting relation until reaching an insert position, the traversal method comprising at a currently traversed data item of the existing relation:

• an order comparing step comprising comparing the data item to be inserted with the currently traversed data item resulting in a current comparison result, and a decision step comprising executing a decision logic for selecting one of a first and second sub-relations of the existing relation based on the current comparison result in order to perform a next action, wherein the next action comprises a selection of a next data item to be traversed or to identify the insert position in the selected sub-relation, wherein each of the first and second sub-relations comprises zero or more data items succeeding and preceding the currently traversed data item respectively, the method comprising:
• predefining a reference data item;
• upon receiving a data item to be inserted, if the relation is empty inserting the received data item into the relation;
• if the relation is not empty inserting the received data item into the relation using the traversal method, wherein the order comparing step comprises:
• in case a comparison result of the currently traversed data item with the reference data item is different from a comparison result of the received data item with the reference data item inverting the decision logic;
• and using the inverted decision logic in the decision step;
• providing the relation.