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

Class ImplementLimitWithTies

java.lang.Object

io.trino.sql.planner.iterative.rule.ImplementLimitWithTies

All Implemented Interfaces:

Rule<LimitNode>

public class ImplementLimitWithTies
extends Object
implements Rule<LimitNode>

Transforms:

 - Limit (row count = x, tiesResolvingScheme(a,b,c))
    - source
 

Into:

 - Project (prune rank symbol)
    - Filter (rank <= x)
       - Window (function: rank, order by a,b,c)
          - source
 

Nested Class Summary

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

Rule.Context, Rule.Result

Constructor Summary

Constructors

Constructor	Description
ImplementLimitWithTies(Metadata metadata)

Method Summary

Modifier and Type	Method	Description
Rule.Result	apply(LimitNode parent, Captures captures, Rule.Context context)
Pattern<LimitNode>	getPattern()	Returns a pattern to which plan nodes this rule applies.
static PlanNode	rewriteLimitWithTiesWithPartitioning(LimitNode limitNode, PlanNode source, Session session, Metadata metadata, PlanNodeIdAllocator idAllocator, SymbolAllocator symbolAllocator, List<Symbol> partitionBy)	Rewrite LimitNode with ties to WindowNode and FilterNode, with partitioning defined by partitionBy.

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 Detail

ImplementLimitWithTies

public ImplementLimitWithTies(Metadata metadata)

Method Detail

getPattern

public Pattern<LimitNode> getPattern()

Description copied from interface: Rule

Returns a pattern to which plan nodes this rule applies.

Specified by:

getPattern in interface Rule<LimitNode>

apply

public Rule.Result apply(LimitNode parent,
                         Captures captures,
                         Rule.Context context)

Specified by:

apply in interface Rule<LimitNode>

rewriteLimitWithTiesWithPartitioning

public static PlanNode rewriteLimitWithTiesWithPartitioning(LimitNode limitNode,
                                                            PlanNode source,
                                                            Session session,
                                                            Metadata metadata,
                                                            PlanNodeIdAllocator idAllocator,
                                                            SymbolAllocator symbolAllocator,
                                                            List<Symbol> partitionBy)

Rewrite LimitNode with ties to WindowNode and FilterNode, with partitioning defined by partitionBy.

This method does not prune outputs of the rewritten plan. After the rewrite, the output consists of source's output symbols and the newly created rankSymbol. Passing all input symbols is intentional, because this method is used for de-correlation in the scenario where the original LimitNode is in the correlated subquery, and the rewrite result is placed on top of de-correlated join. It is the responsibility of the caller to prune redundant outputs.