[HIVE-2324] Enhancing local mode execution with non-HDFS related queries

• Type: New Feature
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Assignee: Unassigned
• Reporter: Ning Zhang
• Created: 29/Jul/11 18:01
• Updated: 29/Jul/11 18:50

Description

Local mode execution are decided based on the input size. There are queries that do not involve data resides in HDFS at all. We should enhance local mode execution with these types of queries:

1) metadata only queries (HIVE-178, HIVE-1003). eg.,

  SELECT max(ds) From T WHERE ts = 'some_partition';  -- both ds and ts are partition columns

2) DUAL table (HIVE-1558):

  SELECT MYUDF('constant1', 'constant2') FROM DUAL;
  SELECT MYUDAF(...) FROM ( SELECT 'const1' col1, 'const2' col2 FROM DUAL ) A GROUP BY col1;