[
https://issues.apache.org/jira/browse/HIVE-13873?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15338884#comment-15338884
]
Ferdinand Xu commented on HIVE-13873:
-------------------------------------
Hi [~spena], could you help review this? Thank you!
> 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
> Assignee: Ferdinand Xu
>
> 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)
