Example of a complex query:
"hello world" @title "example program"~5 @body python -(php|perl) @* codeThe full meaning of this search is:
- Find the words 'hello' and 'world' adjacently in any field in a document;
- Additionally, the same document must also contain the words 'example' and 'program' in the title field, with up to, but not including, 5 words between the words in question; (E.g. "example PHP program" would be matched however "example script to introduce outside data into the correct context for your program" would not because two terms have 5 or more words between them)
- Additionally, the same document must contain the word 'python' in the body field, but not contain either 'php' or 'perl';
- Additionally, the same document must contain the word 'code' in any field.
OR operator precedence is higher than AND, so "looking for cat | dog | mouse" means "looking for ( cat | dog | mouse )" and not "(looking for cat) | dog | mouse".
To understand how a query will be executed, Manticore Search offer query profile tooling for viewing the query tree created by a query expression.
When using SQL statement the full-text query profiling needs to be enabled before running the desired query:
SET profiling =1;
SELECT * FROM test WHERE MATCH('@title abc* @body hey');To view the query tree, we must run SHOW PLAN right after the execution of the query:
SHOW PLAN;The command will return the structure of the executed query. Please note that the 3 statements - SET profiling, the query and SHOW - must run on the same session.
When using the HTTP JSON protocol we can just enable "profile":true to get in response the full-text query tree structure.
{
"index":"test",
"profile":true,
"query":
{
"match_phrase": { "_all" : "had grown quite" }
}
}The response will contain a profile object in which we can find a member query.
query property contains the transformed full-text query tree. Each node contains:
type: node type. Can be AND, OR, PHRASE, KEYWORD etc.description: query subtree for this node shown as a string (inSHOW PLANformat)children: child nodes, if anymax_field_pos: maximum position within a field
A keyword node will also provide:
word: transformed keyword.querypos: position of this keyword in a query.excluded: keyword excluded from query.expanded: keyword added by prefix expansion.field_start: keyword must occur at the very start of the field.field_end: keyword must occur at the very end of the field.boost: keyword IDF will be multiplied by this.
- SQL
- JSON
- PHP
- Python
- javascript
- Java
SET profiling=1;
SELECT * FROM test WHERE MATCH('@title abc* @body hey');
SHOW PLAN \G*************************** 1\. row ***************************
Variable: transformed_tree
Value: AND(
OR(fields=(title), KEYWORD(abcx, querypos=1, expanded), KEYWORD(abcm, querypos=1, expanded)),
AND(fields=(body), KEYWORD(hey, querypos=2)))
1 row in set (0.00 sec)In some cases the evaluated query tree can be rather different from the original one because of expansions and other transformations.
- SQL
- JSON
- PHP
- Python
- javascript
- Java
SET profiling=1;
SELECT id FROM forum WHERE MATCH('@title way* @content hey') LIMIT 1;
SHOW PLAN;Query OK, 0 rows affected (0.00 sec)
+--------+
| id |
+--------+
| 711651 |
+--------+
1 row in set (0.04 sec)
+------------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Variable | Value |
+------------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| transformed_tree | AND(
OR(
OR(
AND(fields=(title), KEYWORD(wayne, querypos=1, expanded)),
OR(
AND(fields=(title), KEYWORD(ways, querypos=1, expanded)),
AND(fields=(title), KEYWORD(wayyy, querypos=1, expanded)))),
AND(fields=(title), KEYWORD(way, querypos=1, expanded)),
OR(fields=(title), KEYWORD(way*, querypos=1, expanded))),
AND(fields=(content), KEYWORD(hey, querypos=2))) |
+------------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)The SQL statement EXPLAIN QUERY allows displaying the execution tree of a provided full-text query without running an actual search query on the table.
- SQL
EXPLAIN QUERY index_base '@title running @body dog'\G EXPLAIN QUERY index_base '@title running @body dog'\G
*************************** 1\. row ***************************
Variable: transformed_tree
Value: AND(
OR(
AND(fields=(title), KEYWORD(run, querypos=1, morphed)),
AND(fields=(title), KEYWORD(running, querypos=1, morphed))))
AND(fields=(body), KEYWORD(dog, querypos=2, morphed)))EXPLAIN QUERY ... option format=dot allows displaying the execution tree of a provided full-text query in hierarchical format suitable for visualization by existing tools, for example https://dreampuf.github.io/GraphvizOnline :
- SQL
EXPLAIN QUERY tbl 'i me' option format=dot\GEXPLAIN QUERY tbl 'i me' option format=dot\G
*************************** 1. row ***************************
Variable: transformed_tree
Value: digraph "transformed_tree"
{
0 [shape=record,style=filled,bgcolor="lightgrey" label="AND"]
0 -> 1
1 [shape=record,style=filled,bgcolor="lightgrey" label="AND"]
1 -> 2
2 [shape=record label="i | { querypos=1 }"]
0 -> 3
3 [shape=record,style=filled,bgcolor="lightgrey" label="AND"]
3 -> 4
4 [shape=record label="me | { querypos=2 }"]
}When expression ranker is used, it is possible to expose the values of the calculated factors using PACKEDFACTORS().
The function returns:
- the values of document level factors (like bm25, field_mask, doc_word_count)
- list with each field that returned a hit (like lcs, hit_count, word_count, sum_idf, min_hit_pos etc.)
- list with each keyword from the query and their tf and idf values
The values can be used to understand why certain documents get scored lower or higher in a search or to improve the existing ranking expression.
- SQL
SELECT id, PACKEDFACTORS() FROM test1 WHERE MATCH('test one') OPTION ranker=expr('1')\G id: 1
packedfactors(): bm25=569, bm25a=0.617197, field_mask=2, doc_word_count=2,
field1=(lcs=1, hit_count=2, word_count=2, tf_idf=0.152356,
min_idf=-0.062982, max_idf=0.215338, sum_idf=0.152356, min_hit_pos=4,
min_best_span_pos=4, exact_hit=0, max_window_hits=1, min_gaps=2,
exact_order=1, lccs=1, wlccs=0.215338, atc=-0.003974),
word0=(tf=1, idf=-0.062982),
word1=(tf=1, idf=0.215338)
1 row in set (0.00 sec)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=0value. 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.
When you run a query via SQL over mysql protocol as a result you get the requested columns back or empty result set in case nothing is found.
- SQL
SELECT * FROM tbl;+------+------+--------+
| id | age | name |
+------+------+--------+
| 1 | 25 | joe |
| 2 | 25 | mary |
| 3 | 33 | albert |
+------+------+--------+
3 rows in set (0.00 sec)In addition to that you can use SHOW META call to see additional meta-information about the latest query.
- SQL
SELECT id,story_author,comment_author FROM hn_small WHERE story_author='joe' LIMIT 3; SHOW META;++--------+--------------+----------------+
| id | story_author | comment_author |
+--------+--------------+----------------+
| 152841 | joe | SwellJoe |
| 161323 | joe | samb |
| 163735 | joe | jsjenkins168 |
+--------+--------------+----------------+
3 rows in set (0.01 sec)
+----------------+-------+
| Variable_name | Value |
+----------------+-------+
| total | 3 |
| total_found | 20 |
| total_relation | gte |
| time | 0.010 |
+----------------+-------+
4 rows in set (0.00 sec)In some cases, e.g. when you do faceted search you can get multiple result sets as a response to your SQL query.
- SQL
SELECT * FROM tbl WHERE MATCH('joe') FACET age;+------+------+
| id | age |
+------+------+
| 1 | 25 |
+------+------+
1 row in set (0.00 sec)
+------+----------+
| age | count(*) |
+------+----------+
| 25 | 1 |
+------+----------+
1 row in set (0.00 sec)In case of a warning the result set will include a warning flag and you can see the warning using SHOW WARNINGS.
- SQL
SELECT * from tbl where match('"joe"/3'); show warnings;+------+------+------+
| id | age | name |
+------+------+------+
| 1 | 25 | joe |
+------+------+------+
1 row in set, 1 warning (0.00 sec)
+---------+------+--------------------------------------------------------------------------------------------+
| Level | Code | Message |
+---------+------+--------------------------------------------------------------------------------------------+
| warning | 1000 | quorum threshold too high (words=1, thresh=3); replacing quorum operator with AND operator |
+---------+------+--------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)If your query fails you will get an error:
- SQL
SELECT * from tbl where match('@surname joe');ERROR 1064 (42000): index idx: query error: no field 'surname' found in schemaVia HTTP JSON iterface 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 searchtimed_out: if the query timed out or nothits: search results. has the following properties:total: total number of matching documentshits: 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.