Patent ID: 8880504

Claim:
A tag management device comprising: a data store which stores a plurality of first tables associated with a of plurality of tags and a second table; and a processor coupled to the data store, wherein the processor executes a process comprising: adding, to a message including data and a plurality of tags received, a sort-free identifier that identifies receiving order, and is monotonically increasing or monotonically decreasing numbers or character strings arranged in alphabetical order or a combination thereof; first storing, in receiving order in all first tables associated with each tag that is included in the received message, only the sort-free identifier added at the adding; second storing, in receiving order in the second table in an associated manner, the sort-free identifier added at the adding and the data which is included in the received message; receiving a search request that includes a search condition being constituted using a plurality of tags; executing an inner join that extracts the sort-free identifier that is stored in common in the each first table associated with each tag that is included in the received search request when the search condition is AND condition, and executing an outer join that extracts the sort-free identifier that is stored in either one of the each first table associated with each tag that is included in the received search request when the search condition is OR condition; and searching the data associated with the extracted sort-free identifier from the second table.