Query Context & Filter Context
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?級搜索的功能:?持多項?本輸?,針對多個字 段進?搜索。
搜索引擎?般也提供基于時間,價格等條件的過濾
在 ElasticSearch 中,有Query 和 Filter 兩種不同 的 Context
Query Context:相關性算分
Filter Context:不需要算分( Yes or No), 可以利? Cache, 獲得更好的性能
條件組合
-
假設要搜索?本電影,包含了以下?些條件
- 評論中包含了 Guitar,?戶打分?于 3 分,同時上映?期要在 1993 與 2000 年之間
-
這個搜索其實包含了 3 段邏輯,針對不同的字段
- 評論字段中要包含 Guitar / ?戶評分?于 3 / 上映?期?期需要在給定的范圍
-
同時包含這三個邏輯,并且有?較好的性能?
復合查詢: bool Query
bool 查詢
?個 bool 查詢,是?個或者多個查詢?句的組合
總共包括 4 種?句。其中 2 種會影響算分,2 種不影響算分
相關性并不只是全?本檢索的專利。也適?于 yes | no 的?句,匹配的?句越多,相關性評分越?。如果多條查詢?句被合并為?條復合查詢語句 ,?如 bool 查詢,則每個查詢?句計算得出的評分會被合并到總的相關性評分中。
關鍵字 | 類型 |
---|---|
must | Query Context 必須匹配。 貢獻算分 |
should | Query Context 選擇性匹配。貢獻算分 |
must_not | Filter Context 查詢字句,必須不能匹配 |
filter | Filter Context 必須匹配,但是不貢獻算分 |
bool 查詢語法
POST /products/_search
{
"query": {
"bool" : {
"must" : {
"term" : { "price" : "30" }
},
"filter": {
"term" : { "avaliable" : "true" }
},
"must_not" : {
"range" : {
"price" : { "lte" : 10 }
}
},
"should" : [
{ "term" : { "productID.keyword" : "JODL-X-1937-#pV7" } },
{ "term" : { "productID.keyword" : "XHDK-A-1293-#fJ3" } }
],
"minimum_should_match" :1
}
}
}
?查詢可以任意順序出現
可以嵌套多個查詢
如果你的 bool 查詢中,沒有 must 條件, should 中必須?少滿??條查詢
如何解決結構化查詢 – “包含?不是相等”的問題
image.png
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- 解決?案:增加?個 genre count 字段進 ?計數
增加 count 字段,使? bool 查詢解決
- 增加 count 字段,使? bool 查詢解決
#改變數據模型,增加字段。解決數組包含而不是精確匹配的問題
POST /newmovies/_bulk
{ "index": { "_id": 1 }}
{ "title" : "Father of the Bridge Part II","year":1995, "genre":"Comedy","genre_count":1 }
{ "index": { "_id": 2 }}
{ "title" : "Dave","year":1993,"genre":["Comedy","Romance"],"genre_count":2 }
#must,有算分
POST /newmovies/_search
{
"query": {
"bool": {
"must": [
{"term": {"genre.keyword": {"value": "Comedy"}}},
{"term": {"genre_count": {"value": 1}}}
]
}
}
}
#Filter。不參與算分,結果的score是0
POST /newmovies/_search
{
"query": {
"bool": {
"filter": [
{"term": {"genre.keyword": {"value": "Comedy"}}},
{"term": {"genre_count": {"value": 1}}}
]
}
}
}
Filter Context – 不影響算分
#Filtering Context
POST _search
{
"query": {
"bool" : {
"filter": {
"term" : { "avaliable" : "true" }
},
"must_not" : {
"range" : {
"price" : { "lte" : 10 }
}
}
}
}
}
image.png
Query Context – 影響算分
POST /products/_search
{
"query": {
"bool": {
"should": [
{
"term": {
"productID.keyword": {
"value": "JODL-X-1937-#pV7"}}
},
{"term": {"avaliable": {"value": true}}
}
]
}
}
}
image.png
bool 嵌套
#嵌套,實現了 should not 邏輯
POST /products/_search
{
"query": {
"bool": {
"must": {
"term": {
"price": "30"
}
},
"should": [
{
"bool": {
"must_not": {
"term": {
"avaliable": "false"
}
}
}
}
],
"minimum_should_match": 1
}
}
}
查詢語句的結構,會對相關度算分產?影響
同?層級下的競爭字段,具有有相同的權重
通過嵌套 bool 查詢,可以改變對算分的影響
POST /animals/_search
{
"query": {
"bool": {
"should": [
{ "term": { "text": "brown" }},
{ "term": { "text": "red" }},
{ "term": { "text": "quick" }},
{ "term": { "text": "dog" }}
]
}
}
}
POST /animals/_search
{
"query": {
"bool": {
"should": [
{ "term": { "text": "quick" }},
{ "term": { "text": "dog" }},
{
"bool":{
"should":[
{ "term": { "text": "brown" }},
{ "term": { "text": "brown" }},
]
}
}
]
}
}
}
控制字段的 Boosting
POST /blogs/_bulk
{ "index": { "_id": 1 }}
{"title":"Apple iPad", "content":"Apple iPad,Apple iPad" }
{ "index": { "_id": 2 }}
{"title":"Apple iPad,Apple iPad", "content":"Apple iPad" }
POST blogs/_search
{
"query": {
"bool": {
"should": [
{"match": {
"title": {
"query": "apple,ipad",
"boost": 1.1
}
}},
{"match": {
"content": {
"query": "apple,ipad",
"boost": 1
}
}}
]
}
}
}
-
Boosting 是控制相關度的?種?段
- 索引,字段 或查詢?條件
-
參數 boost的含義
當 boost > 1 時,打分的相關度相對性提升
當 0 < boost < 1 時,打分的權重相對性降低
當 boost < 0 時,貢獻負分
Not Quite Not
- 要求蘋果公司的產品信息優先
POST /news/_bulk
{ "index": { "_id": 1 }}
{ "content":"Apple Mac" }
{ "index": { "_id": 2 }}
{ "content":"Apple iPad" }
{ "index": { "_id": 3 }}
{ "content":"Apple employee like Apple Pie and Apple Juice" }
POST news/_search
{
"query": {
"bool": {
"must": {
"match":{"content":"apple"}
}
}
}
}
image.png
Boosting Query
POST news/_search
{
"query": {
"bool": {
"must": {
"match":{"content":"apple"}
},
"must_not": {
"match":{"content":"pie"}
}
}
}
}
POST news/_search
{
"query": {
"boosting": {
"positive": {
"match": {
"content": "apple"
}
},
"negative": {
"match": {
"content": "pie"
}
},
"negative_boost": 0.5
}
}
}
本節知識點回顧
Query Context vs. Filter Context
Bool Query – 更多的條件組合
查詢結構與相關性算分
-
如何控制查詢的精確度
- Boosting & Boosting Query
課程demo
POST /products/_bulk
{ "index": { "_id": 1 }}
{ "price" : 10,"avaliable":true,"date":"2018-01-01", "productID" : "XHDK-A-1293-#fJ3" }
{ "index": { "_id": 2 }}
{ "price" : 20,"avaliable":true,"date":"2019-01-01", "productID" : "KDKE-B-9947-#kL5" }
{ "index": { "_id": 3 }}
{ "price" : 30,"avaliable":true, "productID" : "JODL-X-1937-#pV7" }
{ "index": { "_id": 4 }}
{ "price" : 30,"avaliable":false, "productID" : "QQPX-R-3956-#aD8" }
#基本語法
POST /products/_search
{
"query": {
"bool" : {
"must" : {
"term" : { "price" : "30" }
},
"filter": {
"term" : { "avaliable" : "true" }
},
"must_not" : {
"range" : {
"price" : { "lte" : 10 }
}
},
"should" : [
{ "term" : { "productID.keyword" : "JODL-X-1937-#pV7" } },
{ "term" : { "productID.keyword" : "XHDK-A-1293-#fJ3" } }
],
"minimum_should_match" :1
}
}
}
#改變數據模型,增加字段。解決數組包含而不是精確匹配的問題
POST /newmovies/_bulk
{ "index": { "_id": 1 }}
{ "title" : "Father of the Bridge Part II","year":1995, "genre":"Comedy","genre_count":1 }
{ "index": { "_id": 2 }}
{ "title" : "Dave","year":1993,"genre":["Comedy","Romance"],"genre_count":2 }
#must,有算分
POST /newmovies/_search
{
"query": {
"bool": {
"must": [
{"term": {"genre.keyword": {"value": "Comedy"}}},
{"term": {"genre_count": {"value": 1}}}
]
}
}
}
#Filter。不參與算分,結果的score是0
POST /newmovies/_search
{
"query": {
"bool": {
"filter": [
{"term": {"genre.keyword": {"value": "Comedy"}}},
{"term": {"genre_count": {"value": 1}}}
]
}
}
}
#Filtering Context
POST _search
{
"query": {
"bool" : {
"filter": {
"term" : { "avaliable" : "true" }
},
"must_not" : {
"range" : {
"price" : { "lte" : 10 }
}
}
}
}
}
#Query Context
POST /products/_bulk
{ "index": { "_id": 1 }}
{ "price" : 10,"avaliable":true,"date":"2018-01-01", "productID" : "XHDK-A-1293-#fJ3" }
{ "index": { "_id": 2 }}
{ "price" : 20,"avaliable":true,"date":"2019-01-01", "productID" : "KDKE-B-9947-#kL5" }
{ "index": { "_id": 3 }}
{ "price" : 30,"avaliable":true, "productID" : "JODL-X-1937-#pV7" }
{ "index": { "_id": 4 }}
{ "price" : 30,"avaliable":false, "productID" : "QQPX-R-3956-#aD8" }
POST /products/_search
{
"query": {
"bool": {
"should": [
{
"term": {
"productID.keyword": {
"value": "JODL-X-1937-#pV7"}}
},
{"term": {"avaliable": {"value": true}}
}
]
}
}
}
#嵌套,實現了 should not 邏輯
POST /products/_search
{
"query": {
"bool": {
"must": {
"term": {
"price": "30"
}
},
"should": [
{
"bool": {
"must_not": {
"term": {
"avaliable": "false"
}
}
}
}
],
"minimum_should_match": 1
}
}
}
#Controll the Precision
POST _search
{
"query": {
"bool" : {
"must" : {
"term" : { "price" : "30" }
},
"filter": {
"term" : { "avaliable" : "true" }
},
"must_not" : {
"range" : {
"price" : { "lte" : 10 }
}
},
"should" : [
{ "term" : { "productID.keyword" : "JODL-X-1937-#pV7" } },
{ "term" : { "productID.keyword" : "XHDK-A-1293-#fJ3" } }
],
"minimum_should_match" :2
}
}
}
POST /animals/_search
{
"query": {
"bool": {
"should": [
{ "term": { "text": "brown" }},
{ "term": { "text": "red" }},
{ "term": { "text": "quick" }},
{ "term": { "text": "dog" }}
]
}
}
}
POST /animals/_search
{
"query": {
"bool": {
"should": [
{ "term": { "text": "quick" }},
{ "term": { "text": "dog" }},
{
"bool":{
"should":[
{ "term": { "text": "brown" }},
{ "term": { "text": "brown" }},
]
}
}
]
}
}
}
DELETE blogs
POST /blogs/_bulk
{ "index": { "_id": 1 }}
{"title":"Apple iPad", "content":"Apple iPad,Apple iPad" }
{ "index": { "_id": 2 }}
{"title":"Apple iPad,Apple iPad", "content":"Apple iPad" }
POST blogs/_search
{
"query": {
"bool": {
"should": [
{"match": {
"title": {
"query": "apple,ipad",
"boost": 1.1
}
}},
{"match": {
"content": {
"query": "apple,ipad",
"boost":
}
}}
]
}
}
}
DELETE news
POST /news/_bulk
{ "index": { "_id": 1 }}
{ "content":"Apple Mac" }
{ "index": { "_id": 2 }}
{ "content":"Apple iPad" }
{ "index": { "_id": 3 }}
{ "content":"Apple employee like Apple Pie and Apple Juice" }
POST news/_search
{
"query": {
"bool": {
"must": {
"match":{"content":"apple"}
}
}
}
}
POST news/_search
{
"query": {
"bool": {
"must": {
"match":{"content":"apple"}
},
"must_not": {
"match":{"content":"pie"}
}
}
}
}
POST news/_search
{
"query": {
"boosting": {
"positive": {
"match": {
"content": "apple"
}
},
"negative": {
"match": {
"content": "pie"
}
},
"negative_boost": 0.5
}
}
}
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