Package io.deephaven.engine.table.impl

Class SparseSelect

java.lang.Object

io.deephaven.engine.table.impl.SparseSelect

public class SparseSelect
extends Object

A simpler version of TableOperations.select() that is guaranteed to preserve the original table's RowSet.

Like select, the sparseSelected table's columns will be materialized in memory. Unlike select(), sparseSelect guarantees the original Table's RowSet is preserved. Formula columns are not supported, only the names of columns to copy into the output table. This means that each output column is independent of every other output column, which enables column-level parallelism.

Method Summary

Modifier and Type	Method	Description
static Table	partialSparseSelect(Table source, String... columnNames)	Create a copy of the source table with the specified columns materialized.
static Table	partialSparseSelect(Table source, Collection<String> columnNames)	Create a copy of the source table with the specified columns materialized.
static Table	sparseSelect(Table source)	Create a new table with all columns materialized.
static Table	sparseSelect(Table source, String... columnNames)	Create a new table with the specified columns materialized and others dropped.
static Table	sparseSelect(Table source, Collection<String> columnNames)	Create a new table with the specified columns materialized and others dropped.

Methods inherited from class java.lang.Object

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

Method Details

sparseSelect

public static Table sparseSelect(Table source)

Create a new table with all columns materialized.

Parameters:

source - the input table

Returns:

a copy of the source table with materialized column

sparseSelect

public static Table sparseSelect(Table source,
 String... columnNames)

Create a new table with the specified columns materialized and others dropped.

Parameters:

source - the input table

columnNames - the columns to copy to the output

Returns:

a copy of the source table with materialized column

sparseSelect

public static Table sparseSelect(Table source,
 Collection<String> columnNames)

Create a new table with the specified columns materialized and others dropped.

Parameters:

source - the input table

columnNames - the columns to copy to the output

Returns:

a copy of the source table with materialized column

partialSparseSelect

public static Table partialSparseSelect(Table source,
 Collection<String> columnNames)

Create a copy of the source table with the specified columns materialized. Other columns are passed through to the output without changes.

Parameters:

source - the input table

columnNames - the columns to materialize in the output

Returns:

a copy of the source table with materialized columns

partialSparseSelect

public static Table partialSparseSelect(Table source,
 String... columnNames)

Create a copy of the source table with the specified columns materialized. Other columns are passed through to the output without changes.

Parameters:

source - the input table

columnNames - the columns to materialize in the output

Returns:

a copy of the source table with materialized columns