[HIVE-20552] Get Schema from LogicalPlan faster - ASF JIRA

Log work

Agile Board

Rank to Top

Rank to Bottom

Bulk Copy Attachments

Bulk Move Attachments

Voters

Watch issue

Watchers

Create sub-task

Convert to sub-task

Move

Link

Clone

Labels

Update Comment Author

Replace String in Comment

Update Comment Visibility

Delete Comments

XML

Word

Printable

JSON

Details

Type: Improvement
Status: Closed
Priority: Major
Resolution: Fixed
Affects Version/s: None
Fix Version/s: 3.2.0, 4.0.0-alpha-1
Component/s: None
Labels:
- pull-request-available

Description

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:

 if(num == 0) {
 //Schema only
 return new PlanFragment(null, schema, null);
 }

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)}

}