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From "Jinfeng Ni (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (DRILL-2346) Star is not expanded correctly in create view if view fields are specified
Date Fri, 22 May 2015 16:09:17 GMT

    [ https://issues.apache.org/jira/browse/DRILL-2346?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14556372#comment-14556372
] 

Jinfeng Ni commented on DRILL-2346:
-----------------------------------

For now, I think this is the expected behavior.

For select * against a schema-less table, the expanding to a list of regular columns happens
at execution time, not at planning time. However, when Drill creates a view, the view creation
does not involve query execution (execution happens only when you query against the created
view). In stead, it simply goes through query parsing / semantics checking.  It doesn't seem
 possible to expand * into a list of regular columns when execute a view DDL statement, at
this moment.

Also, if you explicitly list the column names in the view's definition, one would argue that
you may put those columns explicitly in the Select statement in stead.

{code}
create view v2 as select a2, b2, c2 from t2;
{code}

or if you want to rename the column into different names

{code}
create view v2 (a3, b3, c3) as select a2, b2, c2 from t2;

or

create view v2 as select a2 a3, b2 b3, c2 c3 from t2;
{code}


> Star is not expanded correctly in create view if view fields are specified
> --------------------------------------------------------------------------
>
>                 Key: DRILL-2346
>                 URL: https://issues.apache.org/jira/browse/DRILL-2346
>             Project: Apache Drill
>          Issue Type: Bug
>          Components: Query Planning & Optimization
>    Affects Versions: 0.8.0
>            Reporter: Victoria Markman
>            Assignee: Jinfeng Ni
>            Priority: Minor
>             Fix For: 1.1.0
>
>
> {code}
> 0: jdbc:drill:schema=dfs> select * from t2 limit 1;
> +------------+------------+------------+
> |     a2     |     b2     |     c2     |
> +------------+------------+------------+
> | 0          | zzz        | 2014-12-31 |
> +------------+------------+------------+
> 1 row selected (0.065 seconds)
> {code}
> We get an error, even though table t2 has 3 columns:
> {code}
> 0: jdbc:drill:schema=dfs> create view v2(a2, b2, c2) as select * from t2;
> +------------+------------+
> |     ok     |  summary   |
> +------------+------------+
> | false      | View's field list and View's query field list have different counts. |
> +------------+------------+
> 1 row selected (0.038 seconds)
> {code}



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