Versions Compared

Old Version 145

changes.mady.by.user Lefty Leverenz

Saved on

compared with

New Version 146

changes.mady.by.user Pengcheng Xiong

Saved on

Key

  • This line was added.
  • This line was removed.
  • Formatting was changed.
Comment: add none to hive.fetch.task.conversion

...

Some select queries can be converted to a single FETCH task, minimizing latency. Currently the query should be single sourced not having any subquery and should not have any aggregations or distincts (which incur RS – ReduceSinkOperator, requiring a MapReduce task), lateral views and joins.

Supported values are none, minimal and more.

0. none: Disable hive.fetch.task.conversion
1. minimal:  SELECT *, FILTER on partition columns (WHERE and HAVING clauses), LIMIT only
2. more:  SELECT, FILTER, LIMIT only (including TABLESAMPLE, virtual columns)

...