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https://issues.apache.org/jira/browse/HIVE-1940?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12990265#comment-12990265
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John Sichi commented on HIVE-1940:
----------------------------------

Hi Anja,

To get a DDL script, you can install Hive and then get your DBMS to generate a 
script.  For example, with MySQL, you can use the mysqldump utility with 
--no-data option.

For Derby, see

http://www.vogella.de/articles/ApacheDerby/article.html#usage_sqldump

For an E/R diagram, I had good results with the open source tool Power 
Architect:

http://www.sqlpower.ca/page/architect

(Some manual layout required after reverse engineering.)  You can see an 
example here:

http://wiki.apache.org/hadoop/Hive/IndexDev#Metastore_Model

If you produce a diagram for the complete metastore, we can get it published in 
the wiki for others to use.


> Query Optimization Using Column Metadata and Histograms
> -------------------------------------------------------
>
>                 Key: HIVE-1940
>                 URL: https://issues.apache.org/jira/browse/HIVE-1940
>             Project: Hive
>          Issue Type: New Feature
>          Components: Metastore, Query Processor
>            Reporter: Anja Gruenheid
>
> The current basis for cost-based query optimization in Hive is information 
> gathered on tables and partitions. To make further improvements in query 
> optimization possible, the next step is to develop and implement 
> possibilities to gather information on columns as discussed in issue HIVE-33. 
> After that, an implementation of histograms is a possible option to use and 
> collect run-time statistics. Next to the actual implementation of these 
> features, it is also necessary to develop a consistent storage model for the 
> MetaStore.

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