Queries may be automatically optimized if OPTION boolean_simplify=1 is specified. Some transformations performed by this optimization include:

• Excess brackets: ((A | B) | C) becomes ( A | B | C ); ((A B) C) becomes ( A B C )
• Excess AND NOT: ((A !N1) !N2) becomes (A !(N1 | N2))
• Common NOT: ((A !N) | (B !N)) becomes ((A|B) !N)
• Common Compound NOT: ((A !(N AA)) | (B !(N BB))) becomes (((A|B) !N) | (A !AA) | (B !BB)) if the cost of evaluating N is greater than the added together costs of evaluating A and B
• Common subterm: ((A (N | AA)) | (B (N | BB))) becomes (((A|B) N) | (A AA) | (B BB)) if the cost of evaluating N is greater than the added together costs of evaluating A and B
• Common keywords: (A | "A B"~N) becomes A; ("A B" | "A B C") becomes "A B"; ("A B"~N | "A B C"~N) becomes ("A B"~N)
• Common phrase: ("X A B" | "Y A B") becomes ("("X"|"Y") A B")
• Common AND NOT: ((A !X) | (A !Y) | (A !Z)) becomes (A !(X Y Z))
• Common OR NOT: ((A !(N | N1)) | (B !(N | N2))) becomes (( (A !N1) | (B !N2) ) !N) Note that optimizing the queries consumes CPU time, so for simple queries -or for hand-optimized queries- you'll do better with the default boolean_simplify=0 value. Simplifications are often better for complex queries, or algorithmically generated queries.

Queries like "-dog", which implicitly include all documents from the collection, can not be evaluated. This is both for technical and performance reasons. Technically, Manticore does not always keep a list of all IDs. Performance-wise, when the collection is huge (ie. 10-100M documents), evaluating such queries could take very long.

Via HTTP JSON interface query result is sent as a JSON document. Example:

{
  "took":10,
  "timed_out": false,
  "hits":
  {
    "total": 2,
    "hits":
    [
      {
        "_id": "1",
        "_score": 1,
        "_source": { "gid": 11 }
      },
      {
        "_id": "2",
        "_score": 1,
        "_source": { "gid": 12 }
      }
    ]
  }
}

• took: time in milliseconds it took to execute the search
• timed_out: if the query timed out or not
• hits: search results. has the following properties:
• total: total number of matching documents
• hits: an array containing matches

Query result can also include query profile information, see Query profile.

Each match in the hits array has the following properties:

• _id: match id
• _score: match weight, calculated by ranker
• _source: an array containing the attributes of this match

By default all attributes are returned in the _source array. You can use the _source property in the request payload to select the fields you want to be included in the result set. Example:

{
  "index":"test",
  "_source":"attr*",
  "query": { "match_all": {} }
}

You can specify the attributes which you want to include in the query result as a string ("_source": "attr*") or as an array of strings ("_source": [ "attr1", "attri*" ]"). Each entry can be an attribute name or a wildcard (*, % and ? symbols are supported).

You can also explicitly specify which attributes you want to include and which to exclude from the result set using the includes and excludes properties:

"_source":
{
  "includes": [ "attr1", "attri*" ],
  "excludes": [ "*desc*" ]
}

An empty list of includes is interpreted as “include all attributes” while an empty list of excludes does not match anything. If an attribute matches both the includes and excludes, then the excludes win.