org.apache.beam.sdk.extensions.sql.zetasql

Class TableResolution

java.lang.Object

org.apache.beam.sdk.extensions.sql.zetasql.TableResolution

public class TableResolution
extends java.lang.Object

Utility methods to resolve a table, given a top-level Calcite schema and a table path.

Constructor Summary

Constructors

Constructor and Description
TableResolution()

Method Summary

Modifier and Type	Method and Description
static org.apache.calcite.schema.Table	resolveCalciteTable(org.apache.calcite.plan.Context context, org.apache.calcite.schema.SchemaPlus schemaPlus, java.util.List<java.lang.String> tablePath) Returns Calcite Table by consulting the schema.

Methods inherited from class java.lang.Object

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

Constructor Detail

TableResolution

public TableResolution()

Method Detail

resolveCalciteTable

public static org.apache.calcite.schema.Table resolveCalciteTable(org.apache.calcite.plan.Context context,
                                                                  org.apache.calcite.schema.SchemaPlus schemaPlus,
                                                                  java.util.List<java.lang.String> tablePath)

Returns Calcite Table by consulting the schema.

The way the schema is queried is defined by the name resolution strategey implemented by a TableResolver and stored as a TableResolutionContext in the context.

If no custom table resolution logic is provided, default one is used, which is: drill down the getSubschema() path until the second-to-last path element. We expect the path to be a table path, so the last element should be a valid table id, we don't expect anything else there.

This resembles a default Calcite planner strategy. One difference is that Calcite doesn't assume the last element is a table and will continue to call getSubschema(), making it impossible for a table provider to understand the context.