[IMPALA-9494] Support displaying complex types

• Type: Epic
• Status: In Progress
• Priority: Major
• Resolution: Unresolved
• Component/s: Backend, Frontend
• Labels: complextype
• Epic Name: Display complex types
• Epic Color: ghx-label-7
• Assignee: Gabor Kaszab
• Reporter: Gabor Kaszab
• Created: 13/Mar/20 14:22
• Updated: 02/Feb/24 18:33

Description

Currently displaying complex types is not supported in Impala. There is a workaround to see the unnested content of the collections but there is no such functionality to display one complex type in one result column formatted to Json. Note, Hive does have support for the same.

The scope of this Jira is to have an umbrella for the following tasks:

• Support all complex types (Struct, Array, Map) in the SELECT list and display them as Json.
• Display complex type columns in Json for a "SELECT *" query
• Allow returning complex types in a sub-select
• Have the display support for Parquet and ORC

Note, I made the sub-tasks as small as possible so that this granularity allows to parallelise the work.

Issue Links

• is duplicated by: IMPALA-2777 Support complex-typed expressions in the select list
• is related to: IMPALA-11148 Unnesting from views work only when alias is provided
• is related to: IMPALA-11847 Refactor table masking views to expose nested columns directly