[ https://issues.apache.org/jira/browse/IMPALA-2272?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Gabor Kaszab updated IMPALA-2272: --------------------------------- Labels: complextype nested_types (was: nested_types) > Parquet scanner always materializes NULL for empty collections > -------------------------------------------------------------- > > Key: IMPALA-2272 > URL: https://issues.apache.org/jira/browse/IMPALA-2272 > Project: IMPALA > Issue Type: Bug > Components: Backend > Affects Versions: Impala 2.3.0 > Reporter: Skye Wanderman-Milne > Priority: Minor > Labels: complextype, nested_types > > Currently the Parquet scanner will always materialize a NULL slot for an > empty collection, rather than an empty ArrayValue/CollectionValue. It is not > currently possible to write a query that exposes this bug (i.e. it's not > possible to write a query that distinguishes between an empty and NULL > collection), but it will be once we add expressions that take collections as > input (e.g. "select array_column is null from tbl"). > We have this bug because the parquet scanner only looks at the repeated field > of an array, not the containing group field. To fix it, it will have to > consider the def/rep levels of both. -- This message was sent by Atlassian Jira (v8.3.4#803005) --------------------------------------------------------------------- To unsubscribe, e-mail: issues-all-unsubscr...@impala.apache.org For additional commands, e-mail: issues-all-h...@impala.apache.org