last name field 34 doe 34 if the record in question contains information on a vehicle the vin vehicle identification number may be the key field 612 also stored on dvd rom 212 is key field matching application 614 matching application 614 is a computer program executable on customer server 214 that is operable to iteratively match the appropriate field in each record on customer database 210 to key field 612 for each record on customer database 210 the application program compares the field with information corresponding to each of key fields 612 until a match is found as each record is matched to the corresponding key field 612 matching application 614 copies the persistent key 610 linked to that key field 612 onto customer database 210 and links that persistent key to the matched record in this way all of the records on customer database 210 are enhanced with the corresponding persistent key from central database 224 for example suppose data customer 214 is a retailer with a list of retail customers the first record of which is a record for customer john doe matching application 614 will compare each key field 612 on dvd rom 212 to the last name field of the record for john doe until a match is found then matching application 614 will copy the persistent key linked to that key field 612 onto the retailer 39 s customer database 224 and link it to the record for retail customer john doe the process thus transforms the data customer 39 s records as shown in step 112 of fig1 into the same records with the appropriate linked persistent key.