Package io.deephaven.engine.table

Interface BasicDataIndex

All Superinterfaces:

LivenessReferent

All Known Subinterfaces:

DataIndex, DataIndexer.RetainableDataIndex

All Known Implementing Classes:

AbstractDataIndex, RemappedDataIndex, StandaloneDataIndex, TableBackedDataIndex, TransformedDataIndex

public interface BasicDataIndex
extends LivenessReferent

Implementations of BasicDataIndex provide a data index for a Table. The index is itself a Table with columns corresponding to the indexed column(s) ("key" columns) and a column of RowSets that contain the row keys for each unique combination of key values (that is, the "group" or "bucket"). The index itself is a Table containing the key column(s) and the RowSets associated with each unique combination of values. Implementations may be loaded from persistent storage or created at runtime, e.g. via aggregations.

Method Summary

Modifier and Type	Method	Description
boolean	isRefreshing()	Whether the index table() is refreshing.
@NotNull List<String>	keyColumnNames()	Get a list of the key column names for the index table.
@NotNull Map<ColumnSource<?>,String>	keyColumnNamesByIndexedColumn()	Get a map from indexed ColumnSources to key column names for the index table.
default @NotNull ColumnSource<?>[]	keyColumns()	Get the key ColumnSources of the index table.
default @NotNull ColumnSource<?>[]	keyColumns(@NotNull ColumnSource<?>[] indexedColumnSources)	Get the key ColumnSources of the index table in the relative order of indexedColumnSources.
default @NotNull ColumnSource<RowSet>	rowSetColumn()	Get the RowSet ColumnSource of the index table.
default @NotNull ColumnSource<RowSet>	rowSetColumn(DataIndexOptions options)	Get the RowSet ColumnSource of the index table.
@NotNull String	rowSetColumnName()	Get the RowSet column name for the index table.
default @NotNull Table	table()	Get the Table backing this data index.
@NotNull Table	table(DataIndexOptions options)	Get the Table backing this data index.
boolean	tableIsCached()	Whether the Table backing this data index is already created and cached.

Methods inherited from interface io.deephaven.engine.liveness.LivenessReferent

dropReference, getReferentDescription, getWeakReference, retainReference, tryRetainReference

Method Details

keyColumnNamesByIndexedColumn

@NotNull
@NotNull Map<ColumnSource<?>,String> keyColumnNamesByIndexedColumn()

Get a map from indexed ColumnSources to key column names for the index table. This map must be ordered in the same order presented by keyColumnNames() and used for lookup keys.

Returns:

A map designating the key column names for each indexed ColumnSource

keyColumnNames

@NotNull
@NotNull List<String> keyColumnNames()

Get a list of the key column names for the index table.

Returns:

The key column names

rowSetColumnName

@NotNull
@NotNull String rowSetColumnName()

Get the RowSet column name for the index table.

Returns:

The RowSet column name

keyColumns

@FinalDefault
@NotNull
default @NotNull ColumnSource<?>[] keyColumns()

Get the key ColumnSources of the index table.

Returns:

An array of the key ColumnSources, to be owned by the caller

keyColumns

@FinalDefault
@NotNull
default @NotNull ColumnSource<?>[] keyColumns(@NotNull
 @NotNull ColumnSource<?>[] indexedColumnSources)

Get the key ColumnSources of the index table in the relative order of indexedColumnSources.

Parameters:

indexedColumnSources - The indexed ColumnSources in the desired order; must match the keys of keyColumnNamesByIndexedColumn()

Returns:

An array of the key ColumnSources in the specified order, to be owned by the caller

rowSetColumn

@FinalDefault
@NotNull
default @NotNull ColumnSource<RowSet> rowSetColumn()

Get the RowSet ColumnSource of the index table.

Returns:

The RowSet ColumnSource

rowSetColumn

@FinalDefault
@NotNull
default @NotNull ColumnSource<RowSet> rowSetColumn(DataIndexOptions options)

Get the RowSet ColumnSource of the index table.

Parameters:

options - parameters for controlling how the the table will be built (if necessary) in order to retrieve the result RowSet ColumnSource

Returns:

The RowSet ColumnSource

tableIsCached

boolean tableIsCached()

Whether the Table backing this data index is already created and cached.

Returns:

true when the table is cached, false otherwise

table

@NotNull
default @NotNull Table table()

Get the Table backing this data index.

The returned table is fully in-memory, equivalent to table(DataIndexOptions) with default options.

Returns:

The Table

table

@NotNull
@NotNull Table table(DataIndexOptions options)

Get the Table backing this data index.

Parameters:

options - parameters to control the returned table

Returns:

The Table

isRefreshing

boolean isRefreshing()

Whether the index table() is refreshing. Some transformations will force the index to become static even when the source table is refreshing.

Returns:

true if the index table() is refreshing, false otherwise