I was testing a service response, (same service same operation different parameters).

When searched by birth date one of the returned results was let's say client id = "CID1234".

So I searched again but this time by client id = "CID1234", same service same operation but this returned no result.

When I raised the issue I was told that client search by Id only returns active clients and that is consistent with observed results.

Somehow I think there must be an equivalent to conservation of energy, there should be conservation of data/information. A record within a same service-operation can not both exist and not exist at the same time depending on the query parameter, as if it was a SQL query for sure it wouldn't make sense, it would break some rule that I can not think what it might be called.

I am including SQL tag because I know for sure if this was a sql query then this situation would not happen, but I do not know why, just that we have always taken it for granted with SQL, can SOA be different?