Xuefu Zhang created HIVE-13873:
----------------------------------
Summary: Column pruning for nested fields
Key: HIVE-13873
URL: https://issues.apache.org/jira/browse/HIVE-13873
Project: Hive
Issue Type: New Feature
Components: Logical Optimizer
Reporter: Xuefu Zhang
Some columnar file formats such as Parquet store fields in struct type also
column by column using encoding described in Google Dramel pager. It's very
common in big data where data are stored in structs while queries only needs a
subset of the the fields in the structs. However, presently Hive still needs to
read the whole struct regardless whether all fields are selected. Therefore,
pruning unwanted sub-fields in struct or nested fields at file reading time
would be a big performance boost for such scenarios.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
