if I wang to update a table, e.g,
 
insert overwrite table mytable
select lower(col1), col2, col3 from mytable;
 
if mytable has many columns but I only need to update one of them, how can I write the
statement short?
 

Hey Richard
         First, don't treat hive as a database. Hive is just an interface above map reduce that help you write SQL like queries that inturn is converted to MR jobs. Saying that hive doesn't support update. 

If you are just experimenting, the query that you wrote would overwrite a whole record (in a broader context a whole partion/table)

Regards
Bejoy.K.S
________________________________
 From: Richard <[EMAIL PROTECTED]>
To: [EMAIL PROTECTED]
Sent: Friday, March 16, 2012 4:26 PM
Subject: update a hive table
 

if I wang to update a table, e.g,
 
insert overwrite table mytable
select lower(col1), col2, col3 from mytable;
 
if mytable has many columns but I only need to update one of them, how can I write the
statement short?

Hi Robert,
Sorry I missed answering your question
>If mytable has many columns but I only need to update one of them, how can I write the
>statement short?
It is not possible in hive. At a bare minimum hive would overwrite a partition (not even a record/file) if you frame an optimized query.
Hope it helps!...

Regards
Bejoy.K.S
________________________________
 From: Bejoy Ks <[EMAIL PROTECTED]>
To: "[EMAIL PROTECTED]" <[EMAIL PROTECTED]>
Sent: Friday, March 16, 2012 5:56 PM
Subject: Re: update a hive table
 

Hey Richard
         First, don't treat hive as a database. Hive is just an interface above map reduce that help you write SQL like queries that inturn is converted to MR jobs. Saying that hive doesn't support update. 

If you are just experimenting, the query that you wrote would overwrite a whole record (in a broader context a whole partion/table)

Regards
Bejoy.K.S
________________________________
 From: Richard <[EMAIL PROTECTED]>
To: [EMAIL PROTECTED]
Sent: Friday, March 16, 2012 4:26 PM
Subject: update a hive table
 

if I wang to update a table, e.g,
 
insert overwrite table mytable
select lower(col1), col2, col3 from mytable;
 
if mytable has many columns but I only need to update one of them, how can I write the
statement short?

create a new table and copy the data from your source table by doing
lower(col1), drop the old table and rename the new table to old table.

On Fri, Mar 16, 2012 at 3:56 AM, Richard <[EMAIL PROTECTED]> wrote:

> if I wang to update a table, e.g,
>
> insert overwrite table mytable
> select lower(col1), col2, col3 from mytable;
>
> if mytable has many columns but I only need to update one of them, how can
> I write the
> statement short?
>
>
>
>

I see, thanks.
At 2012-03-16 20:30:24,"Bejoy Ks" <[EMAIL PROTECTED]> wrote:

Hi Robert,
Sorry I missed answering your question
>If mytable has many columns but I only need to update one of them, how can I write the
>statement short?
It is not possible in hive. At a bare minimum hive would overwrite a partition (not even a record/file) if you frame an optimized query.

Hope it helps!...
Regards
Bejoy.K.S
From: Bejoy Ks <[EMAIL PROTECTED]>
To: "[EMAIL PROTECTED]" <[EMAIL PROTECTED]>
Sent: Friday, March 16, 2012 5:56 PM
Subject: Re: update a hive table

Hey Richard
         First, don't treat hive as a database. Hive is just an interface above map reduce that help you write SQL like queries that inturn is converted to MR jobs. Saying that hive doesn't support update.
If you are just experimenting, the query that you wrote would overwrite a whole record (in a broader context a whole partion/table)
Regards
Bejoy.K.S
From: Richard <[EMAIL PROTECTED]>
To:[EMAIL PROTECTED]
Sent: Friday, March 16, 2012 4:26 PM
Subject: update a hive table

if I wang to update a table, e.g,
 
insert overwrite table mytable
select lower(col1), col2, col3 from mytable;
 
if mytable has many columns but I only need to update one of them, how can I write the
statement short?