OLAP Design

[NLGithubWP]

The COOL can support the following OLAP query:

SELECT cout(*), sum(O_TOTALPRICE) 
FROM TPC_H WHERE O_ORDERPRIORITY = 2-HIGH AND R_NAME = EUROPE
GROUP BY N_NAME,R_NAME 
HAVING O_ORDERDATE >= '1993-01-01' AND O_ORDERDATE <= '1994-01-01' 

The design of OLAP follows the current steps:

1. Run select operator matching records
2. Run group-by according to the given fields
3. Run aggregation on each group.
4. Reformat the result into OLAP format.

The project structure.

The logic visualization.

The result:

{
  "status" : "OK",
  "elapsed" : 0,
  "result" : [ {
    "timeRange" : "1993-01-01|1994-01-01",
    "key" : "RUSSIA|EUROPE",
    "fieldName" : "O_TOTALPRICE",
    "aggregatorResult" : {
      "count" : 2.0,
      "sum" : 312855,
      "average" : null,
      "max" : null,
      "min" : null,
      "countDistinct" : null
    }
  }, {
    "timeRange" : "1993-01-01|1994-01-01",
    "key" : "GERMANY|EUROPE",
    "fieldName" : "O_TOTALPRICE",
    "aggregatorResult" : {
      "count" : 1.0,
      "sum" : 4820,
      "average" : null,
      "max" : null,
      "min" : null,
      "countDistinct" : null
    }
  }, {
    "timeRange" : "1993-01-01|1994-01-01",
    "key" : "ROMANIA|EUROPE",
    "fieldName" : "O_TOTALPRICE",
    "aggregatorResult" : {
      "count" : 2.0,
      "sum" : 190137,
      "average" : null,
      "max" : null,
      "min" : null,
      "countDistinct" : null
    }
  }, {
    "timeRange" : "1993-01-01|1994-01-01",
    "key" : "UNITED KINGDOM|EUROPE",
    "fieldName" : "O_TOTALPRICE",
    "aggregatorResult" : {
      "count" : 1.0,
      "sum" : 33248,
      "average" : null,
      "max" : null,
      "min" : null,
      "countDistinct" : null
    }
  } ]
}

[KimballCai]

Any problem?

[Zrealshadow]

Any problem?

It's a issue to explain the structure of OLAP query.