proxy

The proxy method creates a PartitionedTable.Proxy that allows table operations to be applied to the constituent tables of the source PartitionedTable.

Each operation thus applied will produce a new PartitionedTable with the results, as in transform(UnaryOperator, Dependency...) or partitionedTransform(PartitionedTable, BinaryOperator, Dependency...), and return a new proxy to that PartitionedTable.

Note

If the proxy overload with no parameters is used, the result is the same as proxy(true, false).

Syntax

Parameters

ParameterTypeDescription
requireMatchingKeysboolean

Whether to ensure that both partitioned tables have all the same keys present when a proxied operation uses this and another PartitionedTable as inputs for a partitioned transform.

sanityCheckJoinOperationsboolean

Whether to check that proxied join operations will only find a given join key in one constituent table for this and the table argument if it is also a proxy.

Caution

PartitionedTable transforms and proxies produce different results than on a single-table join (e.g., naturalJoin), whereIn, or whereNotIn when the filter or join keys span partitions. You must ensure that your data's keys map to appropriate partitions to enable correct answers.

When sanityCheckJoins to the proxy method is true, the engine validates that join keys exist only in a single partition, but it does not validate that a key exists in the same partition in both the left and right table.

Returns

A PartitionedTable.Proxy that allows table operations to be applied to the constituent tables of the source PartitionedTable.

Examples