Package io.trino.sql.planner.iterative.rule

Class ImplementExceptAll

java.lang.Object

io.trino.sql.planner.iterative.rule.ImplementExceptAll

All Implemented Interfaces:

Rule<ExceptNode>

public class ImplementExceptAll
extends Object
implements Rule<ExceptNode>

Implement EXCEPT ALL using union, window and filter.

Transforms:

 - Except all
   output: a, b
     - Source1 (a1, b1)
     - Source2 (a2, b2)
     - Source3 (a3, b3)
 

Into:

 - Project (prune helper symbols)
   output: a, b
     - Filter (row_number <= greatest(greatest(count1 - count2, 0) - count3, 0))
         - Window (partition by a, b)
           count1 <- count(marker1)
           count2 <- count(marker2)
           count3 <- count(marker3)
           row_number <- row_number()
               - Union
                 output: a, b, marker1, marker2, marker3
                   - Project (marker1 <- true, marker2 <- null, marker3 <- null)
                       - Source1 (a1, b1)
                   - Project (marker1 <- null, marker2 <- true, marker3 <- null)
                       - Source2 (a2, b2)
                   - Project (marker1 <- null, marker2 <- null, marker3 <- true)
                       - Source3 (a3, b3)
 

Nested Class Summary

Nested classes/interfaces inherited from interface io.trino.sql.planner.iterative.Rule

Rule.Context, Rule.Result

Constructor Summary

Constructors

Constructor	Description
ImplementExceptAll(Metadata metadata)

Method Summary

Modifier and Type	Method	Description
Rule.Result	apply(ExceptNode node, Captures captures, Rule.Context context)
Pattern<ExceptNode>	getPattern()	Returns a pattern to which plan nodes this rule applies.

Methods inherited from class java.lang.Object

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

Methods inherited from interface io.trino.sql.planner.iterative.Rule

isEnabled

Constructor Details

ImplementExceptAll

public ImplementExceptAll(Metadata metadata)

Method Details

getPattern

public Pattern<ExceptNode> getPattern()

Description copied from interface: Rule

Returns a pattern to which plan nodes this rule applies.

Specified by:

getPattern in interface Rule<ExceptNode>

apply

public Rule.Result apply(ExceptNode node,
 Captures captures,
 Rule.Context context)

Specified by:

apply in interface Rule<ExceptNode>