hasDataIndex

Checks if a data index exists for a given table and specified key column(s).

This method is part of the io.deephaven.engine.table.impl.indexer.DataIndexer class and is typically used via a static import.

Syntax

result = hasDataIndex(someTable, "KeyColumn1")
result = hasDataIndex(someTable, "KeyColumn1", "KeyColumn2")
result = hasDataIndex(someTable, ["KeyColumn1", "KeyColumn2"] as String[])

Parameters

Parameter	Type	Description
table	Table	The table to check for an existing data index.
keyColumnNames	String...	The name(s) of the key column(s) defining the index (varargs).
keyColumnNames	String[]	The name(s) of the key column(s) defining the index (array).

Returns

Returns true if a data index exists for the table and key column(s); false otherwise.

Examples

The following example demonstrates how to use hasDataIndex to check for the existence of data indexes on a source table.

import static io.deephaven.engine.table.impl.indexer.DataIndexer.getOrCreateDataIndex
import static io.deephaven.engine.table.impl.indexer.DataIndexer.hasDataIndex

// Create a source table
def sourceTable = emptyTable(100).update(
    "Key1 = (int)i % 10",
    "Key2 = (int)i % 5",
    "Value = i"
)

// Create an index on Key1
def indexKey1 = getOrCreateDataIndex(sourceTable, "Key1")

// Check if an index exists for Key1
def hasIndexOnKey1 = hasDataIndex(sourceTable, "Key1")
println "Index exists on Key1: ${hasIndexOnKey1}"  // Output: true

// Check if an index exists for Key2 (it doesn't yet)
def hasIndexOnKey2 = hasDataIndex(sourceTable, "Key2")
println "Index exists on Key2: ${hasIndexOnKey2}"  // Output: false

// Check if an index exists for Key1 and Key2 (it doesn't yet)
def hasIndexOnKey1Key2 = hasDataIndex(sourceTable, "Key1", "Key2")
println "Index exists on Key1, Key2: ${hasIndexOnKey1Key2}" // Output: false

hasDataIndex

Syntax

Parameters

Returns

Examples

Related documentation