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From "Zheng Shao (JIRA)" <j...@apache.org>
Subject [jira] Commented: (HIVE-626) Typecast bug in Join operator
Date Mon, 13 Jul 2009 00:57:14 GMT

    [ https://issues.apache.org/jira/browse/HIVE-626?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12730176#action_12730176
] 

Zheng Shao commented on HIVE-626:
---------------------------------

Some comments from briefly looking at the ColumnPruner.java code:

1. selectDesc has boolean selectStar and boolean selectStarNoCompute - "SELECT *" is just
a syntactic sugar. We should remove these from the plan.

2. RowResolver is used at compilation stage (to resolve a name like "alias.col" to the actual
fields in the input row object). Why do we need to access RowResolver at all in the optimization
stage? We only need to use RowSchema which can be obtained through "Operator.getSchema()"
call.

3. The following comment from HIVE-460 looks highly suspicious.
"
Yongqiang He added a comment - 13/Jun/09 12:41 AM
Namit, Thanks for correction. Upload a new patch. I guess the diffs came from the order of
file output operator's column names. And the new patch sorted field schemas according to their
names. Hope this can pass the tests. Again it passed in my local. 
"


> Typecast bug in Join operator
> -----------------------------
>
>                 Key: HIVE-626
>                 URL: https://issues.apache.org/jira/browse/HIVE-626
>             Project: Hadoop Hive
>          Issue Type: Bug
>            Reporter: Zheng Shao
>         Attachments: HIVE-626.1.showinfo.patch, HIVE-626.2.showinfo_disable_cp.patch
>
>
> There is a type cast error in Join operator. Produced by the following steps:
> {code}
> create table zshao_foo (foo_id int, foo_name string, foo_a string, foo_b string,
> foo_c string, foo_d string) row format delimited fields terminated by ','
> stored as textfile;
> create table zshao_bar (bar_id int, bar_0 int, foo_id int, bar_1 int, bar_name
> string, bar_a string, bar_b string, bar_c string, bar_d string) row format
> delimited fields terminated by ',' stored as textfile;
> create table zshao_count (bar_id int, n int) row format delimited fields
> terminated by ',' stored as textfile;
> Each table has a single row as follows:
> zshao_foo:
> 1,foo1,a,b,c,d
> zshao_bar:
> 10,0,1,1,bar10,a,b,c,d
> zshao_count:
> 10,2
> load data local inpath 'zshao_foo' overwrite into table zshao_foo;
> load data local inpath 'zshao_bar' overwrite into table zshao_bar;
> load data local inpath 'zshao_count' overwrite into table zshao_count;
> explain extended
> select zshao_foo.foo_name, zshao_bar.bar_name, n from zshao_foo join zshao_bar on zshao_foo.foo_id
=
> zshao_bar.foo_id join zshao_count on zshao_count.bar_id = zshao_bar.bar_id;
> {code}
> The case is from David Lerman.

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