proxy
The proxy method creates a new PartitionedTableProxy from the provided PartitionedTable.
A PartitionedTableProxy is a table operation proxy object for the underlying PartitionedTable. The PartitionedTableProxy gives users access to a variety of Deephaven table operations that are not available to a PartitionedTable. When a user has made all the desired changes to the PartitionedTableProxy, they can use the target attribute to return the underlying PartitionedTable with the changes applied.
A query can achieve the same results by using either transform or a partitioned table proxy. Proxy objects provide convenience by making it simpler to apply transformations to a partitioned table, but with less control.
Syntax
Parameters
| Parameter | Type | Description |
|---|---|---|
| require_matching_keys | bool | Whether to ensure that both |
| sanity_check_joins | bool | Whether to check that for proxied join operations, a given join key only occurs in exactly one constituent table of the underlying |
Caution
PartitionedTable transforms and proxies produce different results than on a single-table join (e.g., natural_join), where_in, or where_not_in 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 the argument 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 PartitionedTableProxy.
Available methods
The following methods are available to a PartitionedTableProxy:
Note
The following links are for the Table version of each of these methods. The PartitionedTableProxy version of each method is identical, except that it returns a PartitionedTableProxy instead of a Table.
abs_sum_byagg_all_byagg_byajavg_bycount_byexact_joinfirst_bygroup_byheadis_refreshingjoinlast_bymax_bymedian_bymin_bynatural_joinrajreverseselectselect_distinctsnapshotsnapshot_whensortsort_descendingstd_bysum_bytailupdateupdate_byupdate_graphupdate_viewvar_byviewweighted_avg_byweighted_sum_bywherewhere_inwhere_not_in
Example
The following example shows how a partitioned table proxy can be used to apply standard table operations to every constituent of a partitioned table. The example uses reverse to reverse the ordering of the original table.