Faceted search is as essential function of a modern search application as autocomplete, spell correction and search keywords highlighting. Especially in E-commerce products.
It comes to the rescue when we deal with large amounts of data and various properties related to each other, whether it is size, color, manufacturer or something else. When querying large amounts of data search results often include large swaths of entries which does not fit user’s expectations. Faceted search allows an end-user to explicitly specify the dimensions that they want their search results to meet.
In Manticore Search there is an optimization that retains the result
set of the original query and reuses it for each facet calculation. As
the aggregations are applied to already calculated subset of documents
they are fast and the total execution time can be in many cases only
marginally bigger than the initial query. Facets can be added to any
query and the facet can be any attribute or expression. A facet result
contains the facet values along with the facet counts. Facets are
available using SQL SELECT statement by declaring them at
the very end of the query.
The facet values can come from an attribute, JSON property from a JSON attribute or expression. Facet values can be also aliased, however the alias must be unique across all result sets (main query results set and other facets results sets). The facet value is taken from the aggregated attribute/expression, but it can also come from another attribute/expression.
FACET {expr_list} [BY {expr_list} ] [DISTINCT {field_name}] [ORDER BY {expr | FACET()} {ASC | DESC}] [LIMIT [offset,] count]Multiple facet declarations need to be separated with a whitespace.
Facets can be defined in the aggs node:
"aggs" :
{
"group name" :
{
"terms" :
{
"field":"attribute name"
}
}
}group name is an alias given to the aggregation, the
field value must contain the name of the attribute or
expression we are faceting.
The result set will contain an aggregations node with
the returned facets, where key is the aggregated value and
doc_count is the aggregation count.
"aggregations": {
"group name": {
"buckets": [
{
"key": 10,
"doc_count": 1019
},
{
"key": 9,
"doc_count": 954
},
{
"key": 8,
"doc_count": 1021
},
{
"key": 7,
"doc_count": 1011
},
{
"key": 6,
"doc_count": 997
}
]
}
} SELECT *, price AS aprice FROM facetdemo LIMIT 10 FACET price LIMIT 10 FACET brand_id LIMIT 5;+------+-------+----------+---------------------+------------+-------------+---------------------------------------+------------+--------+
| id | price | brand_id | title | brand_name | property | j | categories | aprice |
+------+-------+----------+---------------------+------------+-------------+---------------------------------------+------------+--------+
| 1 | 306 | 1 | Product Ten Three | Brand One | Six_Ten | {"prop1":66,"prop2":91,"prop3":"One"} | 10,11 | 306 |
| 2 | 400 | 10 | Product Three One | Brand Ten | Four_Three | {"prop1":69,"prop2":19,"prop3":"One"} | 13,14 | 400 |
...
| 9 | 560 | 6 | Product Two Five | Brand Six | Eight_Two | {"prop1":90,"prop2":84,"prop3":"One"} | 13,14 | 560 |
| 10 | 229 | 9 | Product Three Eight | Brand Nine | Seven_Three | {"prop1":84,"prop2":39,"prop3":"One"} | 12,13 | 229 |
+------+-------+----------+---------------------+------------+-------------+---------------------------------------+------------+--------+
10 rows in set (0.00 sec)
+-------+----------+
| price | count(*) |
+-------+----------+
| 306 | 7 |
| 400 | 13 |
...
| 229 | 9 |
| 595 | 10 |
+-------+----------+
10 rows in set (0.00 sec)
+----------+----------+
| brand_id | count(*) |
+----------+----------+
| 1 | 1013 |
| 10 | 998 |
| 5 | 1007 |
| 8 | 1033 |
| 7 | 965 |
+----------+----------+
5 rows in set (0.00 sec)POST /search -d '
{
"index" : "facetdemo",
"query" : {"match_all" : {} },
"limit": 5,
"aggs" :
{
"group_property" :
{
"terms" :
{
"field":"price",
}
},
"group_brand_id" :
{
"terms" :
{
"field":"brand_id",
}
}
}
}
'{
"took": 3,
"timed_out": false,
"hits": {
"total": 10000,
"hits": [
{
"_id": "1",
"_score": 1,
"_source": {
"price": 197,
"brand_id": 10,
"brand_name": "Brand Ten",
"categories": [
10
]
}
},
...
{
"_id": "5",
"_score": 1,
"_source": {
"price": 805,
"brand_id": 7,
"brand_name": "Brand Seven",
"categories": [
11,
12,
13
]
}
}
]
},
"aggregations": {
"group_property": {
"buckets": [
{
"key": 1000,
"doc_count": 11
},
{
"key": 999,
"doc_count": 12
},
...
{
"key": 991,
"doc_count": 7
}
]
},
"group_brand_id": {
"buckets": [
{
"key": 10,
"doc_count": 1019
},
{
"key": 9,
"doc_count": 954
},
{
"key": 8,
"doc_count": 1021
},
{
"key": 7,
"doc_count": 1011
},
{
"key": 6,
"doc_count": 997
}
]
}
}
}$index->setName('facetdemo');
$search = $index->search('');
$search->limit(5);
$search->facet('price','price');
$search->facet('brand_id','group_brand_id');
$results = $search->get();Array
(
[price] => Array
(
[buckets] => Array
(
[0] => Array
(
[key] => 1000
[doc_count] => 11
)
[1] => Array
(
[key] => 999
[doc_count] => 12
)
[2] => Array
(
[key] => 998
[doc_count] => 7
)
[3] => Array
(
[key] => 997
[doc_count] => 14
)
[4] => Array
(
[key] => 996
[doc_count] => 8
)
)
)
[group_brand_id] => Array
(
[buckets] => Array
(
[0] => Array
(
[key] => 10
[doc_count] => 1019
)
[1] => Array
(
[key] => 9
[doc_count] => 954
)
[2] => Array
(
[key] => 8
[doc_count] => 1021
)
[3] => Array
(
[key] => 7
[doc_count] => 1011
)
[4] => Array
(
[key] => 6
[doc_count] => 997
)
)
)
)res =searchApi.search({"index":"facetdemo","query":{"match_all":{}},"limit":5,"aggs":{"group_property":{"terms":{"field":"price",}},"group_brand_id":{"terms":{"field":"brand_id"}}}}){'aggregations': {u'group_brand_id': {u'buckets': [{u'doc_count': 1019,
u'key': 10},
{u'doc_count': 954,
u'key': 9},
{u'doc_count': 1021,
u'key': 8},
{u'doc_count': 1011,
u'key': 7},
{u'doc_count': 997,
u'key': 6}]},
u'group_property': {u'buckets': [{u'doc_count': 11,
u'key': 1000},
{u'doc_count': 12,
u'key': 999},
{u'doc_count': 7,
u'key': 998},
{u'doc_count': 14,
u'key': 997},
{u'doc_count': 8,
u'key': 996}]}},
'hits': {'hits': [{u'_id': u'1',
u'_score': 1,
u'_source': {u'brand_id': 10,
u'brand_name': u'Brand Ten',
u'categories': [10],
u'price': 197,
u'property': u'Six',
u'title': u'Product Eight One'}},
{u'_id': u'2',
u'_score': 1,
u'_source': {u'brand_id': 6,
u'brand_name': u'Brand Six',
u'categories': [12, 13, 14],
u'price': 671,
u'property': u'Four',
u'title': u'Product Nine Seven'}},
{u'_id': u'3',
u'_score': 1,
u'_source': {u'brand_id': 3,
u'brand_name': u'Brand Three',
u'categories': [13, 14, 15],
u'price': 92,
u'property': u'Six',
u'title': u'Product Five Four'}},
{u'_id': u'4',
u'_score': 1,
u'_source': {u'brand_id': 10,
u'brand_name': u'Brand Ten',
u'categories': [11],
u'price': 713,
u'property': u'Five',
u'title': u'Product Eight Nine'}},
{u'_id': u'5',
u'_score': 1,
u'_source': {u'brand_id': 7,
u'brand_name': u'Brand Seven',
u'categories': [11, 12, 13],
u'price': 805,
u'property': u'Two',
u'title': u'Product Ten Three'}}],
'max_score': None,
'total': 10000},
'profile': None,
'timed_out': False,
'took': 4}res = await searchApi.search({"index":"facetdemo","query":{"match_all":{}},"limit":5,"aggs":{"group_property":{"terms":{"field":"price",}},"group_brand_id":{"terms":{"field":"brand_id"}}}});{"took":0,"timed_out":false,"hits":{"total":10000,"hits":[{"_id":"1","_score":1,"_source":{"price":197,"brand_id":10,"brand_name":"Brand Ten","categories":[10],"title":"Product Eight One","property":"Six"}},{"_id":"2","_score":1,"_source":{"price":671,"brand_id":6,"brand_name":"Brand Six","categories":[12,13,14],"title":"Product Nine Seven","property":"Four"}},{"_id":"3","_score":1,"_source":{"price":92,"brand_id":3,"brand_name":"Brand Three","categories":[13,14,15],"title":"Product Five Four","property":"Six"}},{"_id":"4","_score":1,"_source":{"price":713,"brand_id":10,"brand_name":"Brand Ten","categories":[11],"title":"Product Eight Nine","property":"Five"}},{"_id":"5","_score":1,"_source":{"price":805,"brand_id":7,"brand_name":"Brand Seven","categories":[11,12,13],"title":"Product Ten Three","property":"Two"}}]}}aggs = new HashMap<String,Object>(){{
put("group_property", new HashMap<String,Object>(){{
put("sizes", new HashMap<String,Object>(){{
put("field","price");
}});
}});
put("group_brand_id", new HashMap<String,Object>(){{
put("sizes", new HashMap<String,Object>(){{
put("field","brand_id");
}});
}});
}};
searchRequest = new SearchRequest();
searchRequest.setIndex("facetdemo");
searchRequest.setLimit(5);
query = new HashMap<String,Object>();
query.put("match_all",null);
searchRequest.setQuery(query);
searchRequest.setAggs(aggs);
searchResponse = searchApi.search(searchRequest);class SearchResponse {
took: 0
timedOut: false
aggregations: {group_property={buckets=[{key=1000, doc_count=11}, {key=999, doc_count=12}, {key=998, doc_count=7}, {key=997, doc_count=14}, {key=996, doc_count=8}]}, group_brand_id={buckets=[{key=10, doc_count=1019}, {key=9, doc_count=954}, {key=8, doc_count=1021}, {key=7, doc_count=1011}, {key=6, doc_count=997}]}}
hits: class SearchResponseHits {
maxScore: null
total: 10000
hits: [{_id=1, _score=1, _source={price=197, brand_id=10, brand_name=Brand Ten, categories=[10], title=Product Eight One, property=Six}}, {_id=2, _score=1, _source={price=671, brand_id=6, brand_name=Brand Six, categories=[12, 13, 14], title=Product Nine Seven, property=Four}}, {_id=3, _score=1, _source={price=92, brand_id=3, brand_name=Brand Three, categories=[13, 14, 15], title=Product Five Four, property=Six}}, {_id=4, _score=1, _source={price=713, brand_id=10, brand_name=Brand Ten, categories=[11], title=Product Eight Nine, property=Five}}, {_id=5, _score=1, _source={price=805, brand_id=7, brand_name=Brand Seven, categories=[11, 12, 13], title=Product Ten Three, property=Two}}]
}
profile: null
}Data can be faceted by aggregating another attribute or expression.
For example if the documents contain both the brand id and name, we can
return in facet the brand names, but aggregate the brand ids. This can
be done by using FACET {expr1} BY {expr2}
SELECT * FROM facetdemo FACET brand_name by brand_id;+------+-------+----------+---------------------+-------------+-------------+---------------------------------------+------------+
| id | price | brand_id | title | brand_name | property | j | categories |
+------+-------+----------+---------------------+-------------+-------------+---------------------------------------+------------+
| 1 | 306 | 1 | Product Ten Three | Brand One | Six_Ten | {"prop1":66,"prop2":91,"prop3":"One"} | 10,11 |
| 2 | 400 | 10 | Product Three One | Brand Ten | Four_Three | {"prop1":69,"prop2":19,"prop3":"One"} | 13,14 |
....
| 19 | 855 | 1 | Product Seven Two | Brand One | Eight_Seven | {"prop1":63,"prop2":78,"prop3":"One"} | 10,11,12 |
| 20 | 31 | 9 | Product Four One | Brand Nine | Ten_Four | {"prop1":79,"prop2":42,"prop3":"One"} | 12,13,14 |
+------+-------+----------+---------------------+-------------+-------------+---------------------------------------+------------+
20 rows in set (0.00 sec)
+-------------+----------+
| brand_name | count(*) |
+-------------+----------+
| Brand One | 1013 |
| Brand Ten | 998 |
| Brand Five | 1007 |
| Brand Nine | 944 |
| Brand Two | 990 |
| Brand Six | 1039 |
| Brand Three | 1016 |
| Brand Four | 994 |
| Brand Eight | 1033 |
| Brand Seven | 965 |
+-------------+----------+
10 rows in set (0.00 sec)If you need to remove duplicates from the buckets FACET returns you
can use DISTINCT field_name where field_name
is the field by which you want to do the deduplication. It can be also
id (and it is by default) if you make a FACET query against
a distributed index and are not sure you have unique ids in the indexes
(the indexes should local and have the same schema).
If you have multiple FACET declarations in your query
field_name should be the same in all of them.
DISTINCT returns additional column count(distinct
...) before column count(*), so you can get the both
results without the need to make another query.
SELECT brand_name, property FROM facetdemo FACET brand_name distinct property;+-------------+----------+
| brand_name | property |
+-------------+----------+
| Brand Nine | Four |
| Brand Ten | Four |
| Brand One | Five |
| Brand Seven | Nine |
| Brand Seven | Seven |
| Brand Three | Seven |
| Brand Nine | Five |
| Brand Three | Eight |
| Brand Two | Eight |
| Brand Six | Eight |
| Brand Ten | Four |
| Brand Ten | Two |
| Brand Four | Ten |
| Brand One | Nine |
| Brand Four | Eight |
| Brand Nine | Seven |
| Brand Four | Five |
| Brand Three | Four |
| Brand Four | Two |
| Brand Four | Eight |
+-------------+----------+
20 rows in set (0.00 sec)
+-------------+--------------------------+----------+
| brand_name | count(distinct property) | count(*) |
+-------------+--------------------------+----------+
| Brand Nine | 3 | 3 |
| Brand Ten | 2 | 3 |
| Brand One | 2 | 2 |
| Brand Seven | 2 | 2 |
| Brand Three | 3 | 3 |
| Brand Two | 1 | 1 |
| Brand Six | 1 | 1 |
| Brand Four | 4 | 5 |
+-------------+--------------------------+----------+
8 rows in set (0.00 sec)Facets can aggregate over expressions. A classic example is segmentation of price by certain ranges:
SELECT * FROM facetdemo FACET INTERVAL(price,200,400,600,800) AS price_range ;+------+-------+----------+---------------------+-------------+-------------+---------------------------------------+------------+-------------+
| id | price | brand_id | title | brand_name | property | j | categories | price_range |
+------+-------+----------+---------------------+-------------+-------------+---------------------------------------+------------+-------------+
| 1 | 306 | 1 | Product Ten Three | Brand One | Six_Ten | {"prop1":66,"prop2":91,"prop3":"One"} | 10,11 | 1 |
...
+------+-------+----------+---------------------+-------------+-------------+---------------------------------------+------------+-------------+
20 rows in set (0.00 sec)
+-------------+----------+
| price_range | count(*) |
+-------------+----------+
| 0 | 1885 |
| 3 | 1973 |
| 4 | 2100 |
| 2 | 1999 |
| 1 | 2043 |
+-------------+----------+
5 rows in set (0.01 sec)POST /search -d '
{
"index": "facetdemo",
"query":
{
"match_all": {}
},
"expressions":
{
"price_range": "INTERVAL(price,200,400,600,800)"
},
"aggs":
{
"group_property":
{
"terms":
{
"field": "price_range"
}
}
}
}{
"took": 3,
"timed_out": false,
"hits": {
"total": 10000,
"hits": [
{
"_id": "1",
"_score": 1,
"_source": {
"price": 197,
"brand_id": 10,
"brand_name": "Brand Ten",
"categories": [
10
],
"price_range": 0
}
},
...
{
"_id": "20",
"_score": 1,
"_source": {
"price": 227,
"brand_id": 3,
"brand_name": "Brand Three",
"categories": [
12,
13
],
"price_range": 1
}
}
]
},
"aggregations": {
"group_property": {
"buckets": [
{
"key": 4,
"doc_count": 2100
},
{
"key": 3,
"doc_count": 1973
},
{
"key": 2,
"doc_count": 1999
},
{
"key": 1,
"doc_count": 2043
},
{
"key": 0,
"doc_count": 1885
}
]
}
}
}$index->setName('facetdemo');
$search = $index->search('');
$search->limit(5);
$search->expression('price_range','INTERVAL(price,200,400,600,800)');
$search->facet('price_range','group_property');
$results = $search->get();
print_r($results->getFacets());Array
(
[group_property] => Array
(
[buckets] => Array
(
[0] => Array
(
[key] => 4
[doc_count] => 2100
)
[1] => Array
(
[key] => 3
[doc_count] => 1973
)
[2] => Array
(
[key] => 2
[doc_count] => 1999
)
[3] => Array
(
[key] => 1
[doc_count] => 2043
)
[4] => Array
(
[key] => 0
[doc_count] => 1885
)
)
)
)res =searchApi.search({"index":"facetdemo","query":{"match_all":{}},"expressions":{"price_range":"INTERVAL(price,200,400,600,800)"},"aggs":{"group_property":{"terms":{"field":"price_range"}}}}){'aggregations': {u'group_brand_id': {u'buckets': [{u'doc_count': 1019,
u'key': 10},
{u'doc_count': 954,
u'key': 9},
{u'doc_count': 1021,
u'key': 8},
{u'doc_count': 1011,
u'key': 7},
{u'doc_count': 997,
u'key': 6}]},
u'group_property': {u'buckets': [{u'doc_count': 11,
u'key': 1000},
{u'doc_count': 12,
u'key': 999},
{u'doc_count': 7,
u'key': 998},
{u'doc_count': 14,
u'key': 997},
{u'doc_count': 8,
u'key': 996}]}},
'hits': {'hits': [{u'_id': u'1',
u'_score': 1,
u'_source': {u'brand_id': 10,
u'brand_name': u'Brand Ten',
u'categories': [10],
u'price': 197,
u'property': u'Six',
u'title': u'Product Eight One'}},
{u'_id': u'2',
u'_score': 1,
u'_source': {u'brand_id': 6,
u'brand_name': u'Brand Six',
u'categories': [12, 13, 14],
u'price': 671,
u'property': u'Four',
u'title': u'Product Nine Seven'}},
{u'_id': u'3',
u'_score': 1,
u'_source': {u'brand_id': 3,
u'brand_name': u'Brand Three',
u'categories': [13, 14, 15],
u'price': 92,
u'property': u'Six',
u'title': u'Product Five Four'}},
{u'_id': u'4',
u'_score': 1,
u'_source': {u'brand_id': 10,
u'brand_name': u'Brand Ten',
u'categories': [11],
u'price': 713,
u'property': u'Five',
u'title': u'Product Eight Nine'}},
{u'_id': u'5',
u'_score': 1,
u'_source': {u'brand_id': 7,
u'brand_name': u'Brand Seven',
u'categories': [11, 12, 13],
u'price': 805,
u'property': u'Two',
u'title': u'Product Ten Three'}}],
'max_score': None,
'total': 10000},
'profile': None,
'timed_out': False,
'took': 0}res = await searchApi.search({"index":"facetdemo","query":{"match_all":{}},"expressions":{"price_range":"INTERVAL(price,200,400,600,800)"},"aggs":{"group_property":{"terms":{"field":"price_range"}}}});{"took":0,"timed_out":false,"hits":{"total":10000,"hits":[{"_id":"1","_score":1,"_source":{"price":197,"brand_id":10,"brand_name":"Brand Ten","categories":[10],"title":"Product Eight One","property":"Six","price_range":0}},{"_id":"2","_score":1,"_source":{"price":671,"brand_id":6,"brand_name":"Brand Six","categories":[12,13,14],"title":"Product Nine Seven","property":"Four","price_range":3}},{"_id":"3","_score":1,"_source":{"price":92,"brand_id":3,"brand_name":"Brand Three","categories":[13,14,15],"title":"Product Five Four","property":"Six","price_range":0}},{"_id":"4","_score":1,"_source":{"price":713,"brand_id":10,"brand_name":"Brand Ten","categories":[11],"title":"Product Eight Nine","property":"Five","price_range":3}},{"_id":"5","_score":1,"_source":{"price":805,"brand_id":7,"brand_name":"Brand Seven","categories":[11,12,13],"title":"Product Ten Three","property":"Two","price_range":4}},{"_id":"6","_score":1,"_source":{"price":420,"brand_id":2,"brand_name":"Brand Two","categories":[10,11],"title":"Product Two One","property":"Six","price_range":2}},{"_id":"7","_score":1,"_source":{"price":412,"brand_id":9,"brand_name":"Brand Nine","categories":[10],"title":"Product Four Nine","property":"Eight","price_range":2}},{"_id":"8","_score":1,"_source":{"price":300,"brand_id":9,"brand_name":"Brand Nine","categories":[13,14,15],"title":"Product Eight Four","property":"Five","price_range":1}},{"_id":"9","_score":1,"_source":{"price":728,"brand_id":1,"brand_name":"Brand One","categories":[11],"title":"Product Nine Six","property":"Four","price_range":3}},{"_id":"10","_score":1,"_source":{"price":622,"brand_id":3,"brand_name":"Brand Three","categories":[10,11],"title":"Product Six Seven","property":"Two","price_range":3}},{"_id":"11","_score":1,"_source":{"price":462,"brand_id":5,"brand_name":"Brand Five","categories":[10,11],"title":"Product Ten Two","property":"Eight","price_range":2}},{"_id":"12","_score":1,"_source":{"price":939,"brand_id":7,"brand_name":"Brand Seven","categories":[12,13],"title":"Product Nine Seven","property":"Six","price_range":4}},{"_id":"13","_score":1,"_source":{"price":948,"brand_id":8,"brand_name":"Brand Eight","categories":[12],"title":"Product Ten One","property":"Six","price_range":4}},{"_id":"14","_score":1,"_source":{"price":900,"brand_id":9,"brand_name":"Brand Nine","categories":[12,13,14],"title":"Product Ten Nine","property":"Three","price_range":4}},{"_id":"15","_score":1,"_source":{"price":224,"brand_id":3,"brand_name":"Brand Three","categories":[13],"title":"Product Two Six","property":"Four","price_range":1}},{"_id":"16","_score":1,"_source":{"price":713,"brand_id":10,"brand_name":"Brand Ten","categories":[12],"title":"Product Two Four","property":"Six","price_range":3}},{"_id":"17","_score":1,"_source":{"price":510,"brand_id":2,"brand_name":"Brand Two","categories":[10],"title":"Product Ten Two","property":"Seven","price_range":2}},{"_id":"18","_score":1,"_source":{"price":702,"brand_id":10,"brand_name":"Brand Ten","categories":[12,13],"title":"Product Nine One","property":"Three","price_range":3}},{"_id":"19","_score":1,"_source":{"price":836,"brand_id":4,"brand_name":"Brand Four","categories":[10,11,12],"title":"Product Four Five","property":"Two","price_range":4}},{"_id":"20","_score":1,"_source":{"price":227,"brand_id":3,"brand_name":"Brand Three","categories":[12,13],"title":"Product Three Four","property":"Ten","price_range":1}}]}}searchRequest = new SearchRequest();
expressions = new HashMap<String,Object>(){{
put("price_range","INTERVAL(price,200,400,600,800)");
}};
searchRequest.setExpressions(expressions);
aggs = new HashMap<String,Object>(){{
put("group_property", new HashMap<String,Object>(){{
put("sizes", new HashMap<String,Object>(){{
put("field","price_range");
}});
}});
}};
searchRequest.setIndex("facetdemo");
searchRequest.setLimit(5);
query = new HashMap<String,Object>();
query.put("match_all",null);
searchRequest.setQuery(query);
searchRequest.setAggs(aggs);
searchResponse = searchApi.search(searchRequest);class SearchResponse {
took: 0
timedOut: false
aggregations: {group_property={buckets=[{key=4, doc_count=2100}, {key=3, doc_count=1973}, {key=2, doc_count=1999}, {key=1, doc_count=2043}, {key=0, doc_count=1885}]}}
hits: class SearchResponseHits {
maxScore: null
total: 10000
hits: [{_id=1, _score=1, _source={price=197, brand_id=10, brand_name=Brand Ten, categories=[10], title=Product Eight One, property=Six, price_range=0}}, {_id=2, _score=1, _source={price=671, brand_id=6, brand_name=Brand Six, categories=[12, 13, 14], title=Product Nine Seven, property=Four, price_range=3}}, {_id=3, _score=1, _source={price=92, brand_id=3, brand_name=Brand Three, categories=[13, 14, 15], title=Product Five Four, property=Six, price_range=0}}, {_id=4, _score=1, _source={price=713, brand_id=10, brand_name=Brand Ten, categories=[11], title=Product Eight Nine, property=Five, price_range=3}}, {_id=5, _score=1, _source={price=805, brand_id=7, brand_name=Brand Seven, categories=[11, 12, 13], title=Product Ten Three, property=Two, price_range=4}}]
}
profile: null
}Facets can aggregate over multi-level grouping, the result set being the same as the query would perform a multi-level grouping:
SELECT *,INTERVAL(price,200,400,600,800) AS price_range FROM facetdemo
FACET price_range AS price_range,brand_name ORDER BY brand_name asc;+------+-------+----------+---------------------+-------------+-------------+---------------------------------------+------------+-------------+
| id | price | brand_id | title | brand_name | property | j | categories | price_range |
+------+-------+----------+---------------------+-------------+-------------+---------------------------------------+------------+-------------+
| 1 | 306 | 1 | Product Ten Three | Brand One | Six_Ten | {"prop1":66,"prop2":91,"prop3":"One"} | 10,11 | 1 |
...
+------+-------+----------+---------------------+-------------+-------------+---------------------------------------+------------+-------------+
20 rows in set (0.00 sec)
+--------------+-------------+----------+
| fprice_range | brand_name | count(*) |
+--------------+-------------+----------+
| 1 | Brand Eight | 197 |
| 4 | Brand Eight | 235 |
| 3 | Brand Eight | 203 |
| 2 | Brand Eight | 201 |
| 0 | Brand Eight | 197 |
| 4 | Brand Five | 230 |
| 2 | Brand Five | 197 |
| 1 | Brand Five | 204 |
| 3 | Brand Five | 193 |
| 0 | Brand Five | 183 |
| 1 | Brand Four | 195 |
...Facets support ORDER BY clause as same as a standard
query. Each facet can have it’s or own ordering and the facet ordering
doesn’t affect in any way the ordering of the main result set, which is
ordered by the main query’s ORDER BY. Sorting can be made
on attribute name, count (using COUNT(*)) or special
FACET() function can be used, which provides the aggregated
data values.
SELECT * FROM facetdemo
FACET brand_name BY brand_id ORDER BY FACET() ASC
FACET brand_name BY brand_id ORDER BY brand_name ASC
FACET brand_name BY brand_id order BY COUNT(*) DESC;+------+-------+----------+---------------------+-------------+-------------+---------------------------------------+------------+
| id | price | brand_id | title | brand_name | property | j | categories |
+------+-------+----------+---------------------+-------------+-------------+---------------------------------------+------------+
| 1 | 306 | 1 | Product Ten Three | Brand One | Six_Ten | {"prop1":66,"prop2":91,"prop3":"One"} | 10,11 |
...
| 20 | 31 | 9 | Product Four One | Brand Nine | Ten_Four | {"prop1":79,"prop2":42,"prop3":"One"} | 12,13,14 |
+------+-------+----------+---------------------+-------------+-------------+---------------------------------------+------------+
20 rows in set (0.01 sec)
+-------------+----------+
| brand_name | count(*) |
+-------------+----------+
| Brand One | 1013 |
| Brand Two | 990 |
| Brand Three | 1016 |
| Brand Four | 994 |
| Brand Five | 1007 |
| Brand Six | 1039 |
| Brand Seven | 965 |
| Brand Eight | 1033 |
| Brand Nine | 944 |
| Brand Ten | 998 |
+-------------+----------+
10 rows in set (0.01 sec)
+-------------+----------+
| brand_name | count(*) |
+-------------+----------+
| Brand Eight | 1033 |
| Brand Five | 1007 |
| Brand Four | 994 |
| Brand Nine | 944 |
| Brand One | 1013 |
| Brand Seven | 965 |
| Brand Six | 1039 |
| Brand Ten | 998 |
| Brand Three | 1016 |
| Brand Two | 990 |
+-------------+----------+
10 rows in set (0.01 sec)
+-------------+----------+
| brand_name | count(*) |
+-------------+----------+
| Brand Six | 1039 |
| Brand Eight | 1033 |
| Brand Three | 1016 |
| Brand One | 1013 |
| Brand Five | 1007 |
| Brand Ten | 998 |
| Brand Four | 994 |
| Brand Two | 990 |
| Brand Seven | 965 |
| Brand Nine | 944 |
+-------------+----------+
10 rows in set (0.01 sec)By default each facet result set is limited to 20 values. The number
of facet values can be controlled with LIMIT clause
individually for each facet by providing either a number of values to
return in format LIMIT count or with an offset as
LIMIT offset, count.
The maximum facet values that can be returned is limited by the
query’s max_matches setting. In case dynamic max_matches
(limiting max_matches to offset+per page for better performance) is
wanted to be implemented, it must be taken in account that a too low
max_matches value can hurt the number of facet values. In this case, a
minimum max_matches value should be used good enough to cover the number
of facet values.
SELECT * FROM facetdemo
FACET brand_name BY brand_id ORDER BY FACET() ASC LIMIT 0,1
FACET brand_name BY brand_id ORDER BY brand_name ASC LIMIT 2,4
FACET brand_name BY brand_id order BY COUNT(*) DESC LIMIT 4;+------+-------+----------+---------------------+-------------+-------------+---------------------------------------+------------+
| id | price | brand_id | title | brand_name | property | j | categories |
+------+-------+----------+---------------------+-------------+-------------+---------------------------------------+------------+
| 1 | 306 | 1 | Product Ten Three | Brand One | Six_Ten | {"prop1":66,"prop2":91,"prop3":"One"} | 10,11 |
...
| 20 | 31 | 9 | Product Four One | Brand Nine | Ten_Four | {"prop1":79,"prop2":42,"prop3":"One"} | 12,13,14 |
+------+-------+----------+---------------------+-------------+-------------+---------------------------------------+------------+
20 rows in set (0.01 sec)
+-------------+----------+
| brand_name | count(*) |
+-------------+----------+
| Brand One | 1013 |
+-------------+----------+
1 rows in set (0.01 sec)
+-------------+----------+
| brand_name | count(*) |
+-------------+----------+
| Brand Four | 994 |
| Brand Nine | 944 |
| Brand One | 1013 |
| Brand Seven | 965 |
+-------------+----------+
4 rows in set (0.01 sec)
+-------------+----------+
| brand_name | count(*) |
+-------------+----------+
| Brand Six | 1039 |
| Brand Eight | 1033 |
| Brand Three | 1016 |
+-------------+----------+
3 rows in set (0.01 sec)POST /search -d '
{
"index" : "facetdemo",
"query" : {"match_all" : {} },
"limit": 5,
"aggs" :
{
"group_property" :
{
"terms" :
{
"field":"price",
"size":1,
}
},
"group_brand_id" :
{
"terms" :
{
"field":"brand_id",
"size":3
}
}
}
}
'{
"took": 3,
"timed_out": false,
"hits": {
"total": 10000,
"hits": [
{
"_id": "1",
"_score": 1,
"_source": {
"price": 197,
"brand_id": 10,
"brand_name": "Brand Ten",
"categories": [
10
]
}
},
...
{
"_id": "5",
"_score": 1,
"_source": {
"price": 805,
"brand_id": 7,
"brand_name": "Brand Seven",
"categories": [
11,
12,
13
]
}
}
]
},
"aggregations": {
"group_property": {
"buckets": [
{
"key": 1000,
"doc_count": 11
}
]
},
"group_brand_id": {
"buckets": [
{
"key": 10,
"doc_count": 1019
},
{
"key": 9,
"doc_count": 954
},
{
"key": 8,
"doc_count": 1021
}
]
}
}
}$index->setName('facetdemo');
$search = $index->search('');
$search->limit(5);
$search->facet('price','price',1);
$search->facet('brand_id','group_brand_id',3);
$results = $search->get();
print_r($results->getFacets());
Array
(
[price] => Array
(
[buckets] => Array
(
[0] => Array
(
[key] => 1000
[doc_count] => 11
)
)
)
[group_brand_id] => Array
(
[buckets] => Array
(
[0] => Array
(
[key] => 10
[doc_count] => 1019
)
[1] => Array
(
[key] => 9
[doc_count] => 954
)
[2] => Array
(
[key] => 8
[doc_count] => 1021
)
)
)
)res =searchApi.search({"index":"facetdemo","query":{"match_all":{}},"limit":5,"aggs":{"group_property":{"terms":{"field":"price","size":1,}},"group_brand_id":{"terms":{"field":"brand_id","size":3}}}}){'aggregations': {u'group_brand_id': {u'buckets': [{u'doc_count': 1019,
u'key': 10},
{u'doc_count': 954,
u'key': 9},
{u'doc_count': 1021,
u'key': 8}]},
u'group_property': {u'buckets': [{u'doc_count': 11,
u'key': 1000}]}},
'hits': {'hits': [{u'_id': u'1',
u'_score': 1,
u'_source': {u'brand_id': 10,
u'brand_name': u'Brand Ten',
u'categories': [10],
u'price': 197,
u'property': u'Six',
u'title': u'Product Eight One'}},
{u'_id': u'2',
u'_score': 1,
u'_source': {u'brand_id': 6,
u'brand_name': u'Brand Six',
u'categories': [12, 13, 14],
u'price': 671,
u'property': u'Four',
u'title': u'Product Nine Seven'}},
{u'_id': u'3',
u'_score': 1,
u'_source': {u'brand_id': 3,
u'brand_name': u'Brand Three',
u'categories': [13, 14, 15],
u'price': 92,
u'property': u'Six',
u'title': u'Product Five Four'}},
{u'_id': u'4',
u'_score': 1,
u'_source': {u'brand_id': 10,
u'brand_name': u'Brand Ten',
u'categories': [11],
u'price': 713,
u'property': u'Five',
u'title': u'Product Eight Nine'}},
{u'_id': u'5',
u'_score': 1,
u'_source': {u'brand_id': 7,
u'brand_name': u'Brand Seven',
u'categories': [11, 12, 13],
u'price': 805,
u'property': u'Two',
u'title': u'Product Ten Three'}}],
'max_score': None,
'total': 10000},
'profile': None,
'timed_out': False,
'took': 0}res = await searchApi.search({"index":"facetdemo","query":{"match_all":{}},"limit":5,"aggs":{"group_property":{"terms":{"field":"price","size":1,}},"group_brand_id":{"terms":{"field":"brand_id","size":3}}}});{"took":0,"timed_out":false,"hits":{"total":10000,"hits":[{"_id":"1","_score":1,"_source":{"price":197,"brand_id":10,"brand_name":"Brand Ten","categories":[10],"title":"Product Eight One","property":"Six"}},{"_id":"2","_score":1,"_source":{"price":671,"brand_id":6,"brand_name":"Brand Six","categories":[12,13,14],"title":"Product Nine Seven","property":"Four"}},{"_id":"3","_score":1,"_source":{"price":92,"brand_id":3,"brand_name":"Brand Three","categories":[13,14,15],"title":"Product Five Four","property":"Six"}},{"_id":"4","_score":1,"_source":{"price":713,"brand_id":10,"brand_name":"Brand Ten","categories":[11],"title":"Product Eight Nine","property":"Five"}},{"_id":"5","_score":1,"_source":{"price":805,"brand_id":7,"brand_name":"Brand Seven","categories":[11,12,13],"title":"Product Ten Three","property":"Two"}}]}}searchRequest = new SearchRequest();
aggs = new HashMap<String,Object>(){{
put("group_property", new HashMap<String,Object>(){{
put("sizes", new HashMap<String,Object>(){{
put("field","price");
put("size",1);
}});
}});
put("group_brand_id", new HashMap<String,Object>(){{
put("sizes", new HashMap<String,Object>(){{
put("field","brand_id");
put("size",3);
}});
}});
}};
searchRequest.setIndex("facetdemo");
searchRequest.setLimit(5);
query = new HashMap<String,Object>();
query.put("match_all",null);
searchRequest.setQuery(query);
searchRequest.setAggs(aggs);
searchResponse = searchApi.search(searchRequest);class SearchResponse {
took: 0
timedOut: false
aggregations: {group_property={buckets=[{key=1000, doc_count=11}]}, group_brand_id={buckets=[{key=10, doc_count=1019}, {key=9, doc_count=954}, {key=8, doc_count=1021}]}}
hits: class SearchResponseHits {
maxScore: null
total: 10000
hits: [{_id=1, _score=1, _source={price=197, brand_id=10, brand_name=Brand Ten, categories=[10], title=Product Eight One, property=Six}}, {_id=2, _score=1, _source={price=671, brand_id=6, brand_name=Brand Six, categories=[12, 13, 14], title=Product Nine Seven, property=Four}}, {_id=3, _score=1, _source={price=92, brand_id=3, brand_name=Brand Three, categories=[13, 14, 15], title=Product Five Four, property=Six}}, {_id=4, _score=1, _source={price=713, brand_id=10, brand_name=Brand Ten, categories=[11], title=Product Eight Nine, property=Five}}, {_id=5, _score=1, _source={price=805, brand_id=7, brand_name=Brand Seven, categories=[11, 12, 13], title=Product Ten Three, property=Two}}]
}
profile: null
}When using SQL, a search with facets returns a multiple result sets response. The MySQL client/library/connector used must have support (most do) for multiple result sets in order to be able to access the facet result sets.
Internally, the FACET is a shorthand for executing a
multi-query where the first query contains the main search query and the
rest of the queries in the batch have each a clustering. As in the case
of multi-query, the common query optimization can kick-in for a faceted
search, meaning the search query is executed only once and the facets
operates on the search query result, each facet adding only a fraction
of time to the total query time.
To check if the faceted search ran in an optimized mode can be seen
in query log, where all the
logged queries will contain a xN string, where
N is the number of queries that ran in the optimized group
or checking the output of SHOW META
statement which will exhibit a multiplier metric:
SELECT * FROM facetdemo FACET brand_id FACET price FACET categories;
SHOW META LIKE 'multiplier';+------+-------+----------+---------------------+-------------+-------------+---------------------------------------+------------+
| id | price | brand_id | title | brand_name | property | j | categories |
+------+-------+----------+---------------------+-------------+-------------+---------------------------------------+------------+
| 1 | 306 | 1 | Product Ten Three | Brand One | Six_Ten | {"prop1":66,"prop2":91,"prop3":"One"} | 10,11 |
...
+----------+----------+
| brand_id | count(*) |
+----------+----------+
| 1 | 1013 |
...
+-------+----------+
| price | count(*) |
+-------+----------+
| 306 | 7 |
...
+------------+----------+
| categories | count(*) |
+------------+----------+
| 10 | 2436 |
...
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| multiplier | 4 |
+---------------+-------+
1 row in set (0.00 sec)