Neo4j Legacy关系自动索引密码查询缓慢



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

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