There is support for databases in metastore. But query language doesn't support 
it. Each database could have a separate root/base directory and users can have 
their own databases and can only drop from there. Adding database (or one could 
call it schema) support to QL solves lot of these sharing problems.


________________________________
From: Frederick Oko <[email protected]>
Reply-To: <[email protected]>
Date: Tue, 14 Jul 2009 02:01:50 -0700
To: <[email protected]>
Subject: Re: It there any way sharing directories between different users in  
hive

W/o HIVE-493 behavior and having shared, partitioned base table data such 
schema metadata duplication gets uglier -- while we had multiple schemas in 
general most users fell into a single schema and it is definitely preferred 
that there could be permissioned views in the single schema metadata even to 
reduce clutter of user tables in eg 'show tables'. We had disabled general 
availability of DROP (paranoid code tweak) and you have to be using HDFS 
permissions to protect against insert overwrites.

Also aside from metadata from an HDFS resource mgmt perspective it would have 
been nice if user created tables defaulted to a different root directory than 
schema root e.g. if shared tables in /analytics user tables in 
/analytics_usr/userx -- the external table support allows for such now but the 
use of 'external' is a user behavior that is not inherently enforced. I suppose 
in your per-user schema model u could technically be specifying the root as 
/analytics_usr/userx and created the shared tables as external but such config 
is unwieldy. Actually, w/o doing this HDFS scoping but using Hive schema 
scoping don't you have the possibility of blind conflicts I.e. two users can 
create the same table w/o realizing it and may/maynot pollute each other solely 
on HDFS permissions?

On Jul 13, 2009 10:18 PM, "Min Zhou" <[email protected]> wrote:

Hmm, HIVE-493 is okay since authentication subsystem isn't existing. I was 
considering using something like crontab to automatically add paritions for our 
tables.

Thanks, Prasad!

On Tue, Jul 14, 2009 at 1:05 PM, Prasad Chakka <[email protected]> wrote: > 
> You could fix htt...

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