[ https://issues.apache.org/jira/browse/HIVE-20552?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Teddy Choi updated HIVE-20552: ------------------------------ Status: Patch Available (was: Open) > 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 > Attachments: HIVE-20552.1.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)