joins

The joins attribute is an array of table objects, or references to files containing table objects.

Data from joined tables will be appended to each line of the parent table for processing by parsers.

To preserve system memory when loading data, the columns array is required.

{
  "table": "~/dir_with_source_data/tttt.csv",
  "table_alias": "tttt",
  "joins": [ 
    {
      "table": "~/dir_with_source_data/jjjj.csv", 
      "table_alias": "jjjj", 
      "id_columns": { 
        "jjj1": "ttt1"
      },
      "columns": [ 
        "jjj1",
        "jjj2",
        "jjj3"
      ]
    }
  ]
}

id_columns

usage: required
The id_columns object is a key, value pair of strings which defines the columns used to connect two data sources. The key of this object is a column within the joined table and the value is a column within the parent table.

columns

usage: required
This columns attribute is an array of strings which reference column names in the source data to include during data loading.