Interface MatrixSketch
- All Known Implementing Classes:
CountDistinctFunctionSketch,CountDistinctSketch,KMVSketch
public interface MatrixSketch
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Method Summary
Modifier and TypeMethodDescriptioncreate(MatrixBlock blkIn) Create an initial sketch of a given block.getValue(MatrixBlock blkIn) Get scalar distinct count from an input matrix block.Obtain matrix distinct count value from estimation Used for estimating distinct in rows or columns.intersection(CorrMatrixBlock arg0, CorrMatrixBlock arg1) Intersect two sketchesunion(CorrMatrixBlock arg0, CorrMatrixBlock arg1) Union two sketches together to from a combined sketch.
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Method Details
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getValue
Get scalar distinct count from an input matrix block.- Parameters:
blkIn- An input block to estimate the number of distinct values in- Returns:
- The result matrix block containing the distinct count estimate
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getValueFromSketch
Obtain matrix distinct count value from estimation Used for estimating distinct in rows or columns.- Parameters:
blkIn- The sketch block to extract the count from- Returns:
- The result matrix block
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create
Create an initial sketch of a given block.- Parameters:
blkIn- A block to process- Returns:
- A sketch
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union
Union two sketches together to from a combined sketch.- Parameters:
arg0- Sketch onearg1- Sketch two- Returns:
- The sketch union is a sketch
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intersection
Intersect two sketches- Parameters:
arg0- Sketch onearg1- Sketch two- Returns:
- The sketch intersection is a sketch
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