Question

我想在csv中将一个非常简单的有向图文件导入到OrientDB中。具体而言，该文件是来自SNAP集合https://snap.stanford.edu/data/roadNet-PA.html的roadNet-PA数据集。该文件的第一行如下：

# Directed graph (each unordered pair of nodes is saved once)
# Pennsylvania road network
# Nodes: 1088092 Edges: 3083796
# FromNodeId    ToNodeId
0       1
0       6309
0       6353
1       0
6353    0
6353    6354

只有一种类型的顶点（道路交叉点），边缘没有信息（我认为OrientDB轻量级边缘是最佳选择）。另请注意，顶点用制表符隔开。

我试图创建一个简单的etl来导入文件但没有成功。这是etl：

{
  "config": {
    "log": "debug"
  },
  "source" : {
    "file": { "path": "/tmp/roadNet-PA.csv" }
  },
  "extractor": { "row": {} },
  "transformers": [
    { "csv": { "separator": "   ", "skipFrom": 1, "skipTo": 4 } },
    { "vertex": { "class": "Intersection" } },
    { "edge": { "class": "Road" } }
  ],
  "loader": {
    "orientdb": {
       "dbURL": "remote:localhost/roads",
       "dbType": "graph",
       "classes": [
         {"name": "Intersection", "extends": "V"},
         {"name": "Road", "extends": "E"}
       ], "indexes": [
         {"class":"Intersection", "fields":["id:integer"], "type":"UNIQUE" }
       ]
    }
  }
}

etl可以工作，但它没有像我期望的那样导入文件。我想问题出现在变形金刚中。我的想法是逐行读取csv并创建和边连接两个顶点，但我不知道如何在etl文件中表达它。有什么想法吗？

Answer 1

试试这个：

{
  "config": {
    "log": "debug"
  },
  "source" : {
    "file": { "path": "/tmp/roadNet-PA.csv" }
  },
  "extractor": { "row": {} },
  "transformers": [
    { "csv": { "separator": "\t", "skipFrom": 1, "skipTo": 4,
               "columnsOnFirstLine": false, 
               "columns":["id", "to"] } },
    { "vertex": { "class": "Intersection" } },
    { "merge": { "joinFieldName":"id", "lookup":"Intersection.id" } },
    { "edge": {
       "class": "Road",
       "joinFieldName": "to",
       "lookup": "Intersection.id",
       "unresolvedLinkAction": "CREATE"
      }
    },
  ],
  "loader": {
    "orientdb": {
       "dbURL": "remote:localhost/roads",
       "dbType": "graph",
       "wal": false,
       "batchCommit": 1000,
       "tx": true,
       "txUseLog": false,
       "useLightweightEdges" : true,
       "classes": [
         {"name": "Intersection", "extends": "V"},
         {"name": "Road", "extends": "E"}
       ], "indexes": [
         {"class":"Intersection", "fields":["id:integer"], "type":"UNIQUE" }
       ]
    }
  }
}

为了加速加载，我建议您关闭服务器，并使用“plocal：”而不是“remote：”导入ETL。用以下内容替换现有的示例：

       "dbURL": "plocal:/orientdb/databases/roads",

Answer 2

终于奏效了。我按照Luca的建议在顶点线之前移动了合并。我还将'id'字段更改为'from'以避免错误“属性键保留给所有元素id”。这是片段：

{
  "config": {
    "log": "debug"
  },
  "source" : {
    "file": { "path": "/tmp/roads.csv" }
  },
  "extractor": { "row": {} },
  "transformers": [
    { "csv": { "separator": "\t",
               "columnsOnFirstLine": false, 
               "columns":["from", "to"] } },
    { "merge": { "joinFieldName":"from", "lookup":"Intersection.from" } },
    { "vertex": { "class": "Intersection" } },
    { "edge": {
       "class": "Road",
       "joinFieldName": "to",
       "lookup": "Intersection.from",
       "unresolvedLinkAction": "CREATE"
      }
    },
  ],
  "loader": {
    "orientdb": {
       "dbURL": "remote:localhost/roads",
       "dbType": "graph",
       "wal": false,
       "batchCommit": 1000,
       "tx": true,
       "txUseLog": false,
       "useLightweightEdges" : true,
       "classes": [
         {"name": "Intersection", "extends": "V"},
         {"name": "Road", "extends": "E"}
       ], "indexes": [
         {"class":"Intersection", "fields":["from:integer"], "type":"UNIQUE" }
       ]
    }
  }
}

使用OrientDB ETL将简单的csv文件导入图形的最简单方法

2 个答案: