[ 
https://issues.apache.org/jira/browse/SPARK-19290?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

Apache Spark reassigned SPARK-19290:
------------------------------------

    Assignee: Apache Spark  (was: Wenchen Fan)

> add a new extending interface in Analyzer for post-hoc resolution
> -----------------------------------------------------------------
>
>                 Key: SPARK-19290
>                 URL: https://issues.apache.org/jira/browse/SPARK-19290
>             Project: Spark
>          Issue Type: Improvement
>          Components: SQL
>            Reporter: Wenchen Fan
>            Assignee: Apache Spark
>
> To implement DDL commands, we added several analyzer rules in sql/hive module 
> to analyze DDL related plans. However, our Analyzer currently only have one 
> extending interface: extendedResolutionRules, which defines extra rules that 
> will be run together with other rules in the resolution batch, and doesn't 
> fit DDL rules well, because:
> 1. DDL rules may do some checking and normalization, but we may do it many 
> times as the resolution batch will run rules again and again, until fixed 
> point, and it's hard to tell if a DDL rule has already done its checking and 
> normalization. It's fine because DDL rules are idempotent, but it's bad for 
> analysis performance
> 2. some DDL rules may depend on others, and it's pretty hard to write if 
> conditions to guarantee the dependencies. It will be good if we have a batch 
> which run rules in one pass, so that we can guarantee the dependencies by 
> rules order.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]

Reply via email to