Package io.trino.operator

Class ChangeOnlyUpdatedColumnsMergeProcessor

java.lang.Object

io.trino.operator.ChangeOnlyUpdatedColumnsMergeProcessor

All Implemented Interfaces:

MergeRowChangeProcessor

public class ChangeOnlyUpdatedColumnsMergeProcessor
extends Object
implements MergeRowChangeProcessor

The transformPage() method in this class does two things:

• Transform the input page into an "update" page format
• Removes all rows whose operation number is DEFAULT_CASE_OPERATION_NUMBER

Field Summary

Fields inherited from interface io.trino.operator.MergeRowChangeProcessor

DEFAULT_CASE_OPERATION_NUMBER

Constructor Summary

Constructors

Constructor	Description
ChangeOnlyUpdatedColumnsMergeProcessor(int rowIdChannel, int mergeRowChannel, List<Integer> dataColumnChannels, List<Integer> redistributionColumnChannels)

Method Summary

Modifier and Type	Method	Description
Page	transformPage(Page inputPage)	Transform a page generated by an SQL MERGE operation into page of data columns and operations.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

ChangeOnlyUpdatedColumnsMergeProcessor

public ChangeOnlyUpdatedColumnsMergeProcessor(int rowIdChannel,
 int mergeRowChannel,
 List<Integer> dataColumnChannels,
 List<Integer> redistributionColumnChannels)

Method Details

transformPage

public Page transformPage(Page inputPage)

Description copied from interface: MergeRowChangeProcessor

Transform a page generated by an SQL MERGE operation into page of data columns and operations. The SQL MERGE input page consists of the following:

• The write redistribution columns, if any
• For partitioned or bucketed tables, a hash value column
• The rowId column for the row from the target table if matched, or null if not matched
• The merge case row block

The output page consists of the following:

• All data columns, in table column order
• The operation block
• The rowId block
• The last column in the resulting page is 1 if the row is an insert derived from an update, and zero otherwise.

The DeleteAndInsertMergeProcessor implementation will transform each UPDATE row into multiple rows: an INSERT row and a DELETE row.

Specified by:

transformPage in interface MergeRowChangeProcessor