【发布时间】：2014-06-21 23:19:57
【问题描述】：
我正在 neo4j 中尝试柏林基准 SPARQL 查询。我使用http://michaelbloggs.blogspot.de/2013/05/importing-ttl-turtle-ontologies-in-neo4j.html从三元组创建了 Neo4j 图
总结数据加载，我的图表有以下结构，
Subject => Node
Predicate => Relationship
Object => Node
如果谓词是日期、字符串、整数（原始），则创建属性而不是关系并将其存储在节点中。
现在，我正在尝试跟踪在 Noe4j 中非常慢的查询，
Query 4: Feature with the highest ratio between price with that feature and price without that feature.
corresponding SPARQL query for this,
prefix bsbm: <http://www4.wiwiss.fu-berlin.de/bizer/bsbm/v01/vocabulary/>
prefix bsbm-inst: <http://www4.wiwiss.fu-berlin.de/bizer/bsbm/v01/instances/>
prefix xsd: <http://www.w3.org/2001/XMLSchema#>
Select ?feature ((?sumF*(?countTotal-?countF))/(?countF*(?sumTotal-?sumF)) As ?priceRatio)
{
{ Select (count(?price) As ?countTotal) (sum(xsd:float(str(?price))) As ?sumTotal)
{
?product a <http://www4.wiwiss.fu-berlin.de/bizer/bsbm/v01/instances/ProductType294> .
?offer bsbm:product ?product ;
bsbm:price ?price .
}
}
{ Select ?feature (count(?price2) As ?countF) (sum(xsd:float(str(?price2))) As ?sumF)
{
?product2 a <http://www4.wiwiss.fu-berlin.de/bizer/bsbm/v01/instances/ProductType294> ;
bsbm:productFeature ?feature .
?offer2 bsbm:product ?product2 ;
bsbm:price ?price2 .
}
Group By ?feature
}
}
Order By desc(?priceRatio) ?feature
Limit 100
Cypher query I created for this,
MATCH p1 = (offer1:Offer)-[r1:`product`]->(products1:ProductType294)
MATCH p2 = (offer2:Offer)-[r2:`product`]->products2:ProductType294)-[:`productFeature`]->features
return (sum( DISTINCT offer2.price) * ( count( DISTINCT offer1.price) - count( DISTINCT offer2.price)) /(count(DISTINCT offer2.price)*(sum( DISTINCT offer1.price) - sum(DISTINCT offer2.price)))) AS cnt,features.__URI__ AS frui
ORDER BY cnt DESC,frui
这个查询真的很慢，请让我知道我是否以错误的方式制定查询。
Another query is Query 5: Show the most popular products of a specific product type for each country - by review count ,
prefix bsbm: <http://www4.wiwiss.fu-berlin.de/bizer/bsbm/v01/vocabulary/>
prefix bsbm-inst: <http://www4.wiwiss.fu-berlin.de/bizer/bsbm/v01/instances/>
prefix rev: <http://purl.org/stuff/rev#>
prefix xsd: <http://www.w3.org/2001/XMLSchema#>
Select ?country ?product ?nrOfReviews ?avgPrice
{
{ Select ?country (max(?nrOfReviews) As ?maxReviews)
{
{ Select ?country ?product (count(?review) As ?nrOfReviews)
{
?product a <http://www4.wiwiss.fu-berlin.de/bizer/bsbm/v01/instances/ProductType403> .
?review bsbm:reviewFor ?product ;
rev:reviewer ?reviewer .
?reviewer bsbm:country ?country .
}
Group By ?country ?product
}
}
Group By ?country
}
{ Select ?product (avg(xsd:float(str(?price))) As ?avgPrice)
{
?product a <http://www4.wiwiss.fu-berlin.de/bizer/bsbm/v01/instances/ProductType403> .
?offer bsbm:product ?product .
?offer bsbm:price ?price .
}
Group By ?product
}
{ Select ?country ?product (count(?review) As ?nrOfReviews)
{
?product a <http://www4.wiwiss.fu-berlin.de/bizer/bsbm/v01/instances/ProductType403> .
?review bsbm:reviewFor ?product .
?review rev:reviewer ?reviewer .
?reviewer bsbm:country ?country .
}
Group By ?country ?product
}
FILTER(?nrOfReviews=?maxReviews)
}
Order By desc(?nrOfReviews) ?country ?product
Cypher query I created for this is following,
MATCH (products2:ProductType403)<-[:`reviewFor`]-(reviews:Review)-[:`reviewer`]->(rvrs)-[:`country`]->(countries)
with count(reviews) AS reviewcount,products2.__URI__ AS pruis, countries.__URI__ AS cntrs
MATCH (products1:ProductType403)<-[:`product`]-(offer:Offer)
with AVG(offer.price) AS avgPrice, MAX(reviewcount) AS maxrevs, cntrs
MATCH (products2:ProductType403)<-[:`reviewFor`]-(reviews:Review)-[:`reviewer`]->(rvrs)-[:`country`]->(countries)
with avgPrice, maxrevs,countries, count(reviews) AS rvs, countries.__URI__ AS curis, products2.__URI__ AS puris
where maxrevs=rvs
RETURN curis,puris,rvs,avgPrice
即使是这个查询也很慢。我是否以正确的方式制定查询？
- 我有 10M 三元组（柏林基准数据集）
- 每个类型谓词都转换为标签。
- （对于查询 4）我想要得到的是与价格之间的比率最高的功能
- 该功能和没有该功能的价格。这是正确的方法吗 制定查询？
- （对于查询 4）我得到了此查询的正确结果。
- 如果我不计算总和和计数，则查询会很快执行。
在此先感谢 :) SPARQL 查询和信息可在以下位置找到：http://wifo5-03.informatik.uni-mannheim.de/bizer/berlinsparqlbenchmark/spec/BusinessIntelligenceUseCase/index.html#queries
【问题讨论】：
-
也许您可以共享您导入的数据库，并添加您正在使用的图形模型的模型图片。然后我们可以尝试帮助你。只是从描述中，我真的不明白你在做什么。除了您的查询似乎是图全局查询。
标签： neo4j cypher graph-databases