Arangodb连接查询优化

mkshixfv  于 2022-12-09  发布在  Go
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问题:在数据库中,有3个集合,每个集合包含10,00,000个文档,每个文档中的属性数为150,在每个集合中,**“ID”**属性是唯一的散列索引。

现在我想合并所有集合,并返回所有集合中**“ID”**匹配的文档
例如:集合1包含文档{"id":1,"firstname":"alex","gender":"male"}集合2包含文档{"id":1,"middlename":"wilson","age":23}集合3包含文档{"id":1,"lastname","alive":true}
所以我想返回类似{"id":1,"firstname":"alex","gender":"male","middlename":"wilson","age":23,"lastname","alive":true}文档
查询运行良好,并给我预期的结果,但花了太多的时间在大型收集,所以我想知道任何其他方法来编写查询或任何优化是需要在我的aql

AQL查询:

查询字符串(219个字符,可缓存:真):

FOR c1 IN coll1 
     sort c1.id ASC
         FOR c2 IN coll2
           FOR c3 IN coll3
              FILTER ((c1.id == c2.id ) && (c2.id == c3.id))
              limit 10000
     RETURN MERGE(c1, c2,c3)

AQL解释:

Execution plan:
 Id   NodeType             Est.   Comment
  1   SingletonNode           1   * ROOT
 15   IndexNode         1000000     - FOR c1 IN coll1   /* hash index scan */
 13   IndexNode         1000000       - FOR c2 IN coll2   /* hash index scan */
 12   IndexNode         1000000         - FOR c3 IN coll3   /* hash index scan */
  9   LimitNode           10000           - LIMIT 0, 10000
 10   CalculationNode     10000           - LET #7 = MERGE(c1, c2, c3)   /* simple expression */   /* collections used: c1 : coll1, c2 : coll2, c3 : coll3 */
 11   ReturnNode          10000           - RETURN #7

Indexes used:
 By   Name                      Type   Collection   Unique   Sparse   Selectivity   Fields              Ranges
 15   idx_1650897367446061056   hash   coll1        true     false       100.00 %   [ `id` ]   *
 13   idx_1650897883340210176   hash   coll2        true     false       100.00 %   [ `id` ]   (c1.`id` == c2.`id`)
 12   idx_1650895606437117952   hash   coll3        true     false       100.00 %   [ `id` ]   (c2.`id` == c3.`id`)

Functions used:
 Name    Deterministic   Cacheable   Uses V8
 MERGE   true            true        false  

Optimization rules applied:
 Id   RuleName
  1   use-indexes
  2   remove-filter-covered-by-index
  3   use-index-for-sort
  4   remove-unnecessary-calculations-2
nvbavucw

nvbavucw1#

FOR c1 IN coll1 
 limit 10000
     sort c1.id ASC
         FOR c2 IN coll2
           FOR c3 IN coll3
              FILTER ((c1.id == c2.id ) && (c2.id == c3.id))
     RETURN MERGE(c1, c2,c3)

使用此查询所花费的查询执行时间较少

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