[ArangoDB父级到子级边缘在现有的1毫米文档上创建的嵌套级不起作用/或缓慢

Question

在ArangoDB中创建了events文档。如下所示，已加载100万条记录，并在40秒内完成。

FOR I IN 1..1000000
INSERT {
    "source": "ABC",
    "target": "ABC",
    "type": "REST",
    "attributes" : { "MyAtrib" : TO_STRING(I)},
    "mynum" : I
} INTO events

因此记录1是超级父级，而2是1的子级，依此类推。1 --> 2 --> 3 --> 4 --> ...1000000

创建了空的Edge集合ChildEvents，并尝试通过下面的查询建立父子边缘关系，但是它从未完成（在mynum上创建了哈希索引，但是没有运气）

FOR p IN events
   FOR c IN events
        FILTER p.mynum == ( c.mynum + 1 )
            INSERT { _from: p._id, _to: c._id}  INTO ChildEvents

任何帮助将不胜感激。

Answer 1

创建事件文档在我的系统上花费了大约50秒钟。我在mynum集合中添加了events的索引，并运行了第二个查询（末尾添加了RETURN NEW），处理边缘大约花费了70秒（加上一些时间来渲染他们）：

[我在Windows 10下使用带有RocksDB引擎的ArangoDB 3.6.0，Intel i7-6700K 4x4.0 GHz，32 GB RAM，三星Evo 850 SSD。

您确定索引设置正确吗？解释查询并检查执行计划，也许您有所不同？

Execution plan:
 Id   NodeType                     Est.   Comment
  1   SingletonNode                   1   * ROOT
  3   EnumerateCollectionNode   1000000     - FOR c IN events   /* full collection scan, projections: `mynum`, `_id` */
  9   IndexNode                 1000000       - FOR p IN events   /* persistent index scan, projections: `_id` */
  6   CalculationNode           1000000         - LET #5 = { "_from" : p.`_id`, "_to" : c.`_id` }   /* simple expression */   /* collections used: p : events, c : events */
  7   InsertNode                1000000         - INSERT #5 IN ChildEvents 
  8   ReturnNode                1000000         - RETURN $NEW

Indexes used:
 By   Name                      Type         Collection   Unique   Sparse   Selectivity   Fields        Ranges
  9   idx_1655926293788622848   persistent   events       true     false       100.00 %   [ `mynum` ]   (p.`mynum` == (c.`mynum` + 1))

Optimization rules applied:
 Id   RuleName
  1   move-calculations-up
  2   move-filters-up
  3   interchange-adjacent-enumerations
  4   move-calculations-up-2
  5   move-filters-up-2
  6   remove-data-modification-out-variables
  7   use-indexes
  8   remove-filter-covered-by-index
  9   remove-unnecessary-calculations-2
 10   reduce-extraction-to-projection