LoptMultiJoin (Apache Calcite API)

java.lang.Object
- org.apache.calcite.rel.rules.LoptMultiJoin

```
public class LoptMultiJoin
extends Object
```
Utility class that keeps track of the join factors that make up a MultiJoin.

Constructor Summary

Constructors
Constructor and Description

LoptMultiJoin(MultiJoin multiJoin)

Constructors
Constructor and Description
`LoptMultiJoin(MultiJoin multiJoin)`

Method Summary

All Methods Instance Methods Concrete Methods Deprecated Methods
Modifier and Type	Method and Description
`void`	`addRemovableOuterJoinFactor(int factIdx)` Adds a join factor to the set of factors that can be removed because the factor is the null-generating factor in an outer join, its join keys are unique, and the factor is not projected in the query.
`void`	`addRemovableSelfJoinPair(int factor1, int factor2)` Adds to a map that keeps track of removable self-join pairs.
`org.apache.calcite.rel.rules.LoptMultiJoin.Edge`	`createEdge(RexNode condition)`
`int`	`findRef(int rexInputRef)` Determines the join factor corresponding to a RexInputRef.
`void`	`getChildFactors(LoptJoinTree joinTree, ImmutableBitSet.Builder childFactors)` Deprecated.
`ImmutableBitSet`	`getFactorsRefByFactor(int factIdx)` Returns a bitmap corresponding to the factors referenced by the specified factor in the various join filters that correspond to comparisons.
`ImmutableBitSet`	`getFactorsRefByJoinFilter(RexNode joinFilter)` Returns a bitmap corresponding to the factors referenced within the specified join filter.
`int[][]`	`getFactorWeights()` Returns weights of the different factors relative to one another.
`ImmutableBitSet`	`getFieldsRefByJoinFilter(RexNode joinFilter)` Returns a bitmap corresponding to the fields referenced by a join filter.
`RelNode`	`getJoinFactor(int factIdx)` Returns the factor corresponding to the given factor index.
`int[]`	`getJoinFieldRefCounts(int factIdx)` Returns the join field reference counts for a factor.
`List<RelDataTypeField>`	`getJoinFields(LoptJoinTree left, LoptJoinTree right)` Retrieves the fields corresponding to a join between a left and right tree.
`List<RexNode>`	`getJoinFilters()` Returns all non-outer join filters in this multi-join.
`@Nullable Integer`	`getJoinRemovalFactor(int dimIdx)` Returns the factor id of the fact table corresponding to a dimension table in a semi-join, in the case where the join with the dimension table can be removed.
`LogicalJoin`	`getJoinRemovalSemiJoin(int dimIdx)` Returns the semi-join that allows the join of a dimension table to be removed.
`int`	`getJoinStart(int factIdx)` Returns the starting offset within the multi-join for the specified factor.
`List<RelDataTypeField>`	`getMultiJoinFields()` Returns an array of fields contained within the multi-join.
`MultiJoin`	`getMultiJoinRel()` Returns the MultiJoin corresponding to this multi-join.
`int`	`getNumFieldsInJoinFactor(int factIdx)` Returns the number of fields in a given factor.
`int`	`getNumJoinFactors()` Returns the number of factors in this multi-join.
`int`	`getNumTotalFields()` Returns the total number of fields in the multi-join.
`@Nullable Integer`	`getOtherSelfJoinFactor(int factIdx)` Returns the other factor in a self-join pair if the factor passed in is a factor in a removable self-join; otherwise, returns null.
`@Nullable RexNode`	`getOuterJoinCond(int factIdx)` Returns outer join conditions associated with the specified null-generating factor.
`ImmutableBitSet`	`getOuterJoinFactors(int factIdx)` Returns a bitmap containing the factors that a null-generating factor is dependent upon, if the factor is null-generating in a left or right outer join; otherwise null is returned.
`@Nullable ImmutableBitSet`	`getProjFields(int factIdx)` Returns a bitmap containing the fields that are projected from a factor.
`@Nullable Integer`	`getRightColumnMapping(int rightFactor, int rightOffset)` Determines whether there is a mapping from a column in the right factor of a self-join to a column from the left factor.
`boolean`	`hasAllFactors(LoptJoinTree joinTree, BitSet factorsNeeded)` Returns whether if a join tree contains all factors required.
`boolean`	`isLeftFactorInRemovableSelfJoin(int factIdx)` Returns whether the factor is the left factor in a self-join.
`boolean`	`isNullGenerating(int factIdx)` Returns whether the factor corresponds to a null-generating factor in a left or right outer join.
`boolean`	`isRemovableOuterJoinFactor(int factIdx)` Return whether the factor corresponds to the null-generating factor in an outer join that can be removed.
`boolean`	`isRightFactorInRemovableSelfJoin(int factIdx)` Returns whether the factor is the right factor in a self-join.
`void`	`setFactorWeights()` Sets weighting for each combination of factors, depending on which join filters reference which factors.
`void`	`setJoinRemovalFactor(int dimIdx, int factIdx)` Indicates that a dimension factor's join can be removed because of a semijoin with a fact table.
`void`	`setJoinRemovalSemiJoin(int dimIdx, LogicalJoin semiJoin)` Indicates the semi-join that allows the join of a dimension table to be removed.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - LoptMultiJoin
```
public LoptMultiJoin(MultiJoin multiJoin)
```
- Method Detail
  - getMultiJoinRel
```
public MultiJoin getMultiJoinRel()
```
    Returns the MultiJoin corresponding to this multi-join.
  - getNumJoinFactors
```
public int getNumJoinFactors()
```
    Returns the number of factors in this multi-join.
  - getJoinFactor
```
public RelNode getJoinFactor(int factIdx)
```
    Returns the factor corresponding to the given factor index.
    
    Parameters:
    
    factIdx - Factor to be returned
  - getNumTotalFields
```
public int getNumTotalFields()
```
    Returns the total number of fields in the multi-join.
  - getNumFieldsInJoinFactor
```
public int getNumFieldsInJoinFactor(int factIdx)
```
    Returns the number of fields in a given factor.
    
    Parameters:
    
    factIdx - Desired factor
  - getJoinFilters
```
public List<RexNode> getJoinFilters()
```
    Returns all non-outer join filters in this multi-join.
  - getFactorsRefByJoinFilter
```
public ImmutableBitSet getFactorsRefByJoinFilter(RexNode joinFilter)
```
    Returns a bitmap corresponding to the factors referenced within the specified join filter.
    
    Parameters:
    
    joinFilter - Filter for which information will be returned
  - getMultiJoinFields
```
public List<RelDataTypeField> getMultiJoinFields()
```
    Returns an array of fields contained within the multi-join.
  - getFieldsRefByJoinFilter
```
public ImmutableBitSet getFieldsRefByJoinFilter(RexNode joinFilter)
```
    Returns a bitmap corresponding to the fields referenced by a join filter.
    
    Parameters:
    
    joinFilter - the filter for which information will be returned
  - getFactorWeights
```
public int[][] getFactorWeights()
```
    Returns weights of the different factors relative to one another.
  - getFactorsRefByFactor
```
public ImmutableBitSet getFactorsRefByFactor(int factIdx)
```
    Returns a bitmap corresponding to the factors referenced by the specified factor in the various join filters that correspond to comparisons.
    
    Parameters:
    
    factIdx - Factor for which information will be returned
  - getJoinStart
```
public int getJoinStart(int factIdx)
```
    Returns the starting offset within the multi-join for the specified factor.
    
    Parameters:
    
    factIdx - Factor for which information will be returned
  - isNullGenerating
```
public boolean isNullGenerating(int factIdx)
```
    Returns whether the factor corresponds to a null-generating factor in a left or right outer join.
    
    Parameters:
    
    factIdx - Factor for which information will be returned
  - getOuterJoinFactors
```
public ImmutableBitSet getOuterJoinFactors(int factIdx)
```
    Returns a bitmap containing the factors that a null-generating factor is dependent upon, if the factor is null-generating in a left or right outer join; otherwise null is returned.
    
    Parameters:
    
    factIdx - Factor for which information will be returned
  - getOuterJoinCond
```
public @Nullable RexNode getOuterJoinCond(int factIdx)
```
    Returns outer join conditions associated with the specified null-generating factor.
    
    Parameters:
    
    factIdx - Factor for which information will be returned
  - getProjFields
```
public @Nullable ImmutableBitSet getProjFields(int factIdx)
```
    Returns a bitmap containing the fields that are projected from a factor.
    
    Parameters:
    
    factIdx - Factor for which information will be returned
  - getJoinFieldRefCounts
```
public int[] getJoinFieldRefCounts(int factIdx)
```
    Returns the join field reference counts for a factor.
    
    Parameters:
    
    factIdx - Factor for which information will be returned
  - getJoinRemovalFactor
```
public @Nullable Integer getJoinRemovalFactor(int dimIdx)
```
    Returns the factor id of the fact table corresponding to a dimension table in a semi-join, in the case where the join with the dimension table can be removed.
    
    Parameters:
    
    dimIdx - Dimension factor for which information will be returned
  - getJoinRemovalSemiJoin
```
public LogicalJoin getJoinRemovalSemiJoin(int dimIdx)
```
    Returns the semi-join that allows the join of a dimension table to be removed.
    
    Parameters:
    
    dimIdx - Dimension factor for which information will be returned
  - setJoinRemovalFactor
```
public void setJoinRemovalFactor(int dimIdx,
                                 int factIdx)
```
    Indicates that a dimension factor's join can be removed because of a semijoin with a fact table.
    
    Parameters:
    
    dimIdx - Dimension factor
    
    factIdx - Fact factor
  - setJoinRemovalSemiJoin
```
public void setJoinRemovalSemiJoin(int dimIdx,
                                   LogicalJoin semiJoin)
```
    Indicates the semi-join that allows the join of a dimension table to be removed.
    
    Parameters:
    
    dimIdx - Dimension factor
    
    semiJoin - the semijoin
  - findRef
```
@RequiresNonNull(value={"joinStart","nFieldsInJoinFactor"})
public int findRef(@UnknownInitialization LoptMultiJoin this,
                                                                               int rexInputRef)
```
    Determines the join factor corresponding to a RexInputRef.
    
    Parameters:
    
    rexInputRef - rexInputRef index
    
    Returns:
    
    index corresponding to join factor
  - setFactorWeights
```
public void setFactorWeights()
```
    Sets weighting for each combination of factors, depending on which join filters reference which factors. Greater weight is given to equality conditions. Also, sets bitmaps indicating which factors are referenced by each factor within join filters that are comparisons.
  - hasAllFactors
```
public boolean hasAllFactors(LoptJoinTree joinTree,
                             BitSet factorsNeeded)
```
    Returns whether if a join tree contains all factors required.
    
    Parameters:
    
    joinTree - Join tree to be examined
    
    factorsNeeded - Bitmap of factors required
    
    Returns:
    
    true if join tree contains all required factors
  - getChildFactors
```
@Deprecated
public void getChildFactors(LoptJoinTree joinTree,
                                        ImmutableBitSet.Builder childFactors)
```
    Deprecated.
    
    Sets a bitmap indicating all child RelNodes in a join tree.
    
    Parameters:
    
    joinTree - join tree to be examined
    
    childFactors - bitmap to be set
  - getJoinFields
```
public List<RelDataTypeField> getJoinFields(LoptJoinTree left,
                                            LoptJoinTree right)
```
    Retrieves the fields corresponding to a join between a left and right tree.
    
    Parameters:
    
    left - left hand side of the join
    
    right - right hand side of the join
    
    Returns:
    
    fields of the join
  - addRemovableOuterJoinFactor
```
public void addRemovableOuterJoinFactor(int factIdx)
```
    Adds a join factor to the set of factors that can be removed because the factor is the null-generating factor in an outer join, its join keys are unique, and the factor is not projected in the query.
    
    Parameters:
    
    factIdx - Join factor
  - isRemovableOuterJoinFactor
```
public boolean isRemovableOuterJoinFactor(int factIdx)
```
    Return whether the factor corresponds to the null-generating factor in an outer join that can be removed.
    
    Parameters:
    
    factIdx - Factor in question
  - addRemovableSelfJoinPair
```
public void addRemovableSelfJoinPair(int factor1,
                                     int factor2)
```
    Adds to a map that keeps track of removable self-join pairs.
    
    Parameters:
    
    factor1 - one of the factors in the self-join
    
    factor2 - the second factor in the self-join
  - getOtherSelfJoinFactor
```
public @Nullable Integer getOtherSelfJoinFactor(int factIdx)
```
    Returns the other factor in a self-join pair if the factor passed in is a factor in a removable self-join; otherwise, returns null.
    
    Parameters:
    
    factIdx - one of the factors in a self-join pair
  - isLeftFactorInRemovableSelfJoin
```
public boolean isLeftFactorInRemovableSelfJoin(int factIdx)
```
    Returns whether the factor is the left factor in a self-join.
    
    Parameters:
    
    factIdx - Factor in a self-join
  - isRightFactorInRemovableSelfJoin
```
public boolean isRightFactorInRemovableSelfJoin(int factIdx)
```
    Returns whether the factor is the right factor in a self-join.
    
    Parameters:
    
    factIdx - Factor in a self-join
  - getRightColumnMapping
```
public @Nullable Integer getRightColumnMapping(int rightFactor,
                                               int rightOffset)
```
    Determines whether there is a mapping from a column in the right factor of a self-join to a column from the left factor. Assumes that the right factor is a part of a self-join.
    
    Parameters:
    
    rightFactor - the index of the right factor
    
    rightOffset - the column offset of the right factor
    
    Returns:
    
    the offset of the corresponding column in the left factor, if such a column mapping exists; otherwise, null is returned
  - createEdge
```
public org.apache.calcite.rel.rules.LoptMultiJoin.Edge createEdge(RexNode condition)
```

Class LoptMultiJoin

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

LoptMultiJoin

Method Detail

getMultiJoinRel

getNumJoinFactors

getJoinFactor

getNumTotalFields

getNumFieldsInJoinFactor

getJoinFilters

getFactorsRefByJoinFilter

getMultiJoinFields

getFieldsRefByJoinFilter

getFactorWeights

getFactorsRefByFactor

getJoinStart

isNullGenerating

getOuterJoinFactors

getOuterJoinCond

getProjFields

getJoinFieldRefCounts

getJoinRemovalFactor

getJoinRemovalSemiJoin

setJoinRemovalFactor

setJoinRemovalSemiJoin

findRef

setFactorWeights

hasAllFactors

getChildFactors

getJoinFields

addRemovableOuterJoinFactor

isRemovableOuterJoinFactor

addRemovableSelfJoinPair

getOtherSelfJoinFactor

isLeftFactorInRemovableSelfJoin

isRightFactorInRemovableSelfJoin

getRightColumnMapping

createEdge