Data storage and retrieval system and method for storing cell coordinates in a computer memory

A method of storing and retrieving data, the method carried out on a first computing device that is communicatively linked to a second computing device that displays a spreadsheet that includes a plurality of occupied cells and to an external data store, the method comprising:

• the first computing device
• maintaining nodes of an RTree, wherein the nodes contain minimum bounding rectangles of the plurality of occupied cells;
• mapping display coordinates of the plurality of occupied cells to coordinates of the nodes;
• retrieving the plurality of nodes from the data store;
• in response to a row being inserted into the spreadsheet between adjacent rows of the spreadsheet as displayed, and without retrieving further nodes from the data store, updating the mapping to include a fractional coordinate of one of the nodes, which contains a minimum bounding rectangle for the inserted row, and leaving the RTree unchanged;
• and
• in response to a row of the spreadsheet being deleted, updating and re-inserting nodes with ranges containing start or stop rows corresponding to the deleted row,
• wherein the fractional coordinate is between coordinates of nodes containing minimum bounding rectangles for the adjacent rows.

A method for storing data to and retrieving data from a computer memory, the method carried out by a first computing device and comprising:

• configuring the computer memory according to an RTree representing a structure of a spreadsheet displayed on a second computing device;
• configuring the RTree according to a map,
• wherein the RTree comprises a plurality of nodes, at least some of which contain one or more minimum bounding rectangles, each minimum bounding rectangle encompassing coordinates of one or more cells of the spreadsheet,
• wherein the spreadsheet comprises a first row and a second row,
• mapping a coordinate of the first row as displayed to a coordinate of a first node of the RTree;
• mapping a coordinate of the second row as displayed to a coordinate of a second node of the RTree;
• retrieving the plurality of nodes from the data store;
• in response to a row being inserted between the first row and the second row of the spreadsheet as displayed, and without retrieving further nodes from the data store, updating the map to include a mapping between the inserted row to a fractional coordinate that is between the coordinate of the first node and the coordinate of the second node and leaving the RTree unchanged;
• and
• in response to a row of the spreadsheet being deleted, updating and re-inserting nodes with ranges containing start or stop rows corresponding to the deleted row.