[jira] [Resolved] (HIVE-20552) Get Schema from LogicalPlan faster

["Teddy Choi (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/HIVE-20552?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Teddy Choi resolved HIVE-20552.
-------------------------------
    Resolution: Fixed

> Get Schema from LogicalPlan faster
> ----------------------------------
>
>                 Key: HIVE-20552
>                 URL: https://issues.apache.org/jira/browse/HIVE-20552
>             Project: Hive
>          Issue Type: Improvement
>            Reporter: Teddy Choi
>            Assignee: Teddy Choi
>            Priority: Major
>              Labels: pull-request-available
>             Fix For: 4.0.0, 3.2.0
>
>         Attachments: HIVE-20552.1.patch, HIVE-20552.2.patch, HIVE-20552.3.patch
>
>
> To get the schema of a query faster, it currently needs to compile, optimize, and generate a TezPlan, which creates extra overhead when only the LogicalPlan is needed.
> 1. Copy the method \{{HiveMaterializedViewsRegistry.parseQuery}}, making it \{{public static}} and putting it in a utility class. 
> 2. Change the return statement of the method to \{{return analyzer.getResultSchema();}}
> 3. Change the return type of the method to \{{List<FieldSchema>}}
> 4. Call the new method from \{{GenericUDTFGetSplits.createPlanFragment}} replacing the current code which does this:
> {code}
>  if(num == 0) {
>  //Schema only
>  return new PlanFragment(null, schema, null);
>  }
> {code}
> moving the call earlier in \{{getPlanFragment}} ... right after the HiveConf is created ... bypassing the code that uses \{{HiveTxnManager}} and \{{Driver}}.
> 5. Convert the \{{List<FieldSchema>}} to \{{org.apache.hadoop.hive.llap.Schema}}.
> 6. return from \{{getPlanFragment}} by returning \{{new PlanFragment(null, schema, null)}}



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)