[
https://issues.apache.org/jira/browse/HIVE-6439?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13902557#comment-13902557
]
Brock Noland commented on HIVE-6439:
------------------------------------
1) There are many tabs and spacing issues in this patch
2) We are catching throwable and logging at debug. We should *never* do this.
{noformat}
} catch (Throwable t) {
LOG.debug("CBO failed, skipping CBO", t);
{noformat}
> Introduce CBO step in Semantic Analyzer
> ---------------------------------------
>
> Key: HIVE-6439
> URL: https://issues.apache.org/jira/browse/HIVE-6439
> Project: Hive
> Issue Type: Sub-task
> Reporter: Harish Butani
> Assignee: Harish Butani
> Attachments: HIVE-6439.1.patch
>
>
> This patch introduces CBO step in SemanticAnalyzer. For now the
> CostBasedOptimizer is an empty shell.
> The contract between SemAly and CBO is:
> - CBO step is controlled by the 'hive.enable.cbo.flag'.
> - When true Hive SemAly will hand CBO a Hive Operator tree (with operators
> annotated with stats). If it can CBO will return a better plan in Hive AST
> form.
--
This message was sent by Atlassian JIRA
(v6.1.5#6160)
