节点
1000000 x ({prop:'a'})
1000000 x ({prop:'b'})
1000000 x ({prop:'c'})
节点集=~3MegaNodes
Obs.:道具不是唯一的道具。
关系
1000 x [:TYPEA {date:20150301} ]
1000 x [:TYPEA {date:20150228} ]
1000 x [:TYPEA {date:20150227} ]
1000 x [:TYPEA {date:........} ]
1000 x [:TYPEA {date:19000101} ]
1000 x [:TYPEB {date:20150301} ]
1000 x [:TYPEB {date:20150228} ]
1000 x [:TYPEB {date:20150227} ]
1000 x [:TYPEB {date:........} ]
1000 x [:TYPEB {date:19000101} ]
TYPEA=42062天x 1000 rels
TYPEA=~42 000 000
类型b=~42 000 000
关系集=~84兆Rels
我想匹配模式:
MATCH (n1 {prop:'a'}) -[ r1:TYPEA {date:20001231} ]-> (n2 {prop:'b'})
RETURN n2;
通过索引改进
我的neo4j.properties:
relationship_auto_indexing=true
relationship_keys_indexable=date
密码查询:
START
r1 = relationship:relationship_auto_index('date:20001231')
MATCH (n1 {prop:'a'}) -[r1:TYPEA]-> (n2 {prop:'b'})
RETURN n2;
:)好好工作!
现在,我想匹配模式:
MATCH
(n1 {prop:'a'})
-[ r1:TYPEA {date:20001231} ]->
(n2 {prop:'b'})
-[ r2:TYPEA {date:20001231} ]->
(n3 {prop:'c'})
RETURN n2, n3;
然后我尝试:
START
r1 = relationship:relationship_auto_index('date:20001231'),
r2 = relationship:relationship_auto_index('date:20001231')
MATCH (n1 {prop:'a'}) -[r1:TYPEA]-> (n2 {prop:'b'}) -[r2:TYPEA]-> (n3 {prop:'c'})
RETURN DISTINCT n2, n3;
:(慢速运行。
因为笛卡尔乘积产生了许多中间结果。1000^2。
一方面,不可能在查询中多次使用同一标识符。
另一方面,Labels索引(Schema)不适用于关系。
还有希望吗?(发布:Neo4j-community-2.2.0)
在查询密码中不使用子句start时,关系遗留索引有什么好处?
Thanx
这修改了概念查询,但效果良好:
START
r = relationship:relationship_auto_index('date:20001231')
WITH [x IN COLLECT(r) WHERE TYPE(x)='TYPEA'] AS cr
UNWIND cr AS r1
MATCH (n1 {prop:'a'}) -[r1]-> (n2 {prop:'b'})
WITH DISTINCT n2, cr
UNWIND cr AS r2
MATCH (n2) -[r2]-> (n3 {prop:'c'})
RETURN DISTINCT n2, n3;
Thx