tajo-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Jihoon Son <jihoon...@apache.org>
Subject [FYI] JSON query execution is available
Date Wed, 14 May 2014 06:06:17 GMT
Hi folks,

Tajo now supports the query execution of JSON form.
Here is an example of JSON representation of a SQL query.

SQL> select count(*) from region

  "IsDistinct": false,
  "Projections": [
      "Expr": {
        "IsDistinct": false,
        "Signature": "count",
        "FuncParams": [],
        "OpType": "CountRowsFunction"
      "OpType": "Target"
  "Expr": {
    "Relations": [
        "TableName": "region",
        "OpType": "Relation"
    "OpType": "RelationList"
  "OpType": "Projection"

More detailed information of JSON representation can be found at

To execute JSON queries, executeQueryWithJson() is added to TajoClient.
In addition, JSON queries can be currently executed via TajoCli. We plan to
provide a simple JSON cli, soon (TAJO-826).

I expect that this feature will be useful for various OLAP applications
which use TAJO as their query engine.


  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message