Query Difference

Dear Team,
I followed documentation and trying to understand queries and here is my confusion:

  1. Query Set A returns appropriate results (where _type=filesystem and fs.used_p=0

  2. But all "Query Set B" query results are returning _type=process and others...there is no _type=filesystem in the result at all.

Please explain where my understanding is wrong?

*it's standard topbeat index+document

Query Set A:
get topbeat-2016.03.17/_search?q=fs.used_p=0.56

Query Set B:
get topbeat-2016.03.17/_search
{"query": {"fs.used_p":0.56}}

get topbeat-2016.03.17/_search
{"filter": {"fs.used_p":0.56}}

get topbeat-2016.03.17/_search
{"query": {"match_all": {}},
"filter": {"fs.used_p":0.56}
}

Regards...