u201d coordinates records below are some c c definitions of how to convert back and forth between decimal degrees and vns hashed unit system next is the description of the vns record with can hold in its opaque content either a deal type data or an alert type data qword cm content mask 64 bit flags to filter sites if 0 for use by older clients in case we add more fields before buf ignored by vns since vns is compiled with any latest vnsdrec amp expiration time gmt from 32 bit c time function the vns database lookup works on the header of the two attached payloads the 1st is the store info such as address phone number and other non deal related info the 2nd is the deal payload such as 15 off ladies dresses the master slave record flags with the associated record numbers allows the vns to substitute a deal payload from the master record to the slave record payload very quickly by doing this chain stores need only update the master record deal payload in the database and any lookup on perhaps 30 000 slave stores will be sent with the response data when the vns server is setting up the deal and alert databases the deal records are sorted in increasing x location order and the alert records are sorted in 2 tables of lower left x1 and upper right x2 in increasing x location order use mx and my as the device 39 s location n1 as number of alerts vl as the alert left edge table vr as the alert right edge one n2 as number of deals v as the deal table for deals.