Page History

...

• INSERT OVERWRITE statements to directories, local directories and tables (or partitions) can all be used together within the same query.
• INSERT OVERWRITE statements to HDFS filesystem directories is the best way to extract large amounts of data from Hive. Hive can write to HDFS directories in parallel from within a map-reduce job.
• The directory is, as you would expect, OVERWRITten, in other words, if the specified path exists, it is clobbered and replaced with the output.

Truncating tables

Syntax

TRUNCATE TABLE table_name [PARTITION partition_spec];

partition_spec:
  : (partition_col = partition_col_value, partition_col = partiton_col_value, ...)

Synopsis

• Removes all rows from a table or partition(s).
• Table should be native/managed table (or exception will be thrown).

Notes

• User can specify partial partition spec for truncating multiple partitions at once.
• Without partition spec, all partitions in the table will be truncated.