[jira] [Comment Edited] (HIVE-14053) Hive should report that primary keys can't be null.

["Ashutosh Chauhan (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/HIVE-14053?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15757465#comment-15757465 ] 

Ashutosh Chauhan edited comment on HIVE-14053 at 12/17/16 7:27 PM:
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There is another column called NULLABLE which can also be populated like IS_NULLABLE in resultset. It will good to update that too.


was (Author: ashutoshc):
There is another column called NULLABLE which can also be populated like IS_NULLABLE in resultset. Good to update that.

> Hive should report that primary keys can't be null.
> ---------------------------------------------------
>
>                 Key: HIVE-14053
>                 URL: https://issues.apache.org/jira/browse/HIVE-14053
>             Project: Hive
>          Issue Type: Bug
>            Reporter: Carter Shanklin
>            Assignee: Pengcheng Xiong
>            Priority: Minor
>         Attachments: HIVE-14053.01.patch
>
>
> HIVE-13076 introduces "rely novalidate" primary and foreign keys to Hive. With the right driver in place, tools like Tableau can do join elimination and queries can run much faster.
> Some gaps remain, currently getAttributes() in HiveDatabaseMetaData doesn't work quite right for keys. In particular, primary keys by definition are not null and the metadata should reflect this for improved join elimination.
> In this example that uses the TPC-H schema and its constraints, we sum l_extendedprice and group by l_shipmode. This query should not use more than just the lineitem table.
> With all the constraints in place, Tableau generates this query:
> {code}
> SELECT `lineitem`.`l_shipmode` AS `l_shipmode`,
>   SUM(`lineitem`.`l_extendedprice`) AS `sum_l_extendedprice_ok`
> FROM `tpch_bin_flat_orc_2`.`lineitem` `lineitem`
>   JOIN `tpch_bin_flat_orc_2`.`orders` `orders` ON (`lineitem`.`l_orderkey` = `orders`.`o_orderkey`)
>   JOIN `tpch_bin_flat_orc_2`.`customer` `customer` ON (`orders`.`o_custkey` = `customer`.`c_custkey`)
>   JOIN `tpch_bin_flat_orc_2`.`nation` `nation` ON (`customer`.`c_nationkey` = `nation`.`n_nationkey`)
> WHERE ((((NOT (`lineitem`.`l_partkey` IS NULL)) AND (NOT (`lineitem`.`l_suppkey` IS NULL))) AND ((NOT (`lineitem`.`l_partkey` IS NULL)) AND (NOT (`lineitem`.`l_suppkey` IS NULL)))) AND (NOT (`nation`.`n_regionkey` IS NULL)))
> {code}
> Since these are the primary keys the denormalization and the where condition is unnecessary and this sort of query can be a lot faster by just accessing the lineitem table.



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