Package com.cupoftea.table

Class DataFrameJoiner

java.lang.Object

com.cupoftea.table.DataFrameJoiner

public final class DataFrameJoiner
extends Object

Vectorized Columnar Hash Join engine operating directly on ColumnVector storage.

Eliminates row-level object materialization (Row, JoinKey, HashMap) by:

1. Build Phase: Constructing a flat primitive-array chained hash table (int[] bucketHead, int[] nextRowIdx) with specialized zero-boxing fast-paths for int, long, dictionary codes, and UTF-8 byte slices (StringColumnVector).
2. Probe Phase: Partitioning the probe table across parallel worker chunks to emit primitive gather index pairs (leftMatchIdx, rightMatchIdx) (with -1 indicating unmatched null rows).
3. Gather Phase: Materializing output ColumnVectors in bulk via indexed array gather and lock-free two-pass UTF-8 byte compaction.

Method Summary

Modifier and Type	Method	Description
static IDataFrame	asOfJoin(IDataFrame left, IDataFrame right, String leftOn, String rightOn, List<String> leftBy, List<String> rightBy, AsOfDirection direction, String leftSuffix, String rightSuffix)
static IDataFrame	join(IDataFrame left, IDataFrame right, JoinType how, List<String> leftOn, List<String> rightOn, String leftSuffix, String rightSuffix)

Methods inherited from class java.lang.Object

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

Method Details

join

public static IDataFrame join(IDataFrame left,
 IDataFrame right,
 JoinType how,
 List<String> leftOn,
 List<String> rightOn,
 String leftSuffix,
 String rightSuffix)

asOfJoin

public static IDataFrame asOfJoin(IDataFrame left,
 IDataFrame right,
 String leftOn,
 String rightOn,
 List<String> leftBy,
 List<String> rightBy,
 AsOfDirection direction,
 String leftSuffix,
 String rightSuffix)