org.apache.beam.sdk.extensions.sql.meta

Interface CustomTableResolver

All Superinterfaces:

TableProvider

All Known Implementing Classes:

DataCatalogTableProvider, FullNameTableProvider

public interface CustomTableResolver
extends TableProvider

Interface that table providers can implement if they require custom table name resolution.

registerKnownTableNames(List) is called by the parser/planner and takes the list of all tables mentioned in the query. Then when normal Calcite lifecycle is executed the table provider can now check against this list and perform custom resolution. This is a workaround for lack of context in Calcite's logic, e.g. it's impossible to receive the whole table name at once, or understand that it has done querying sub-schemas and expects a table.

Method Summary

Modifier and Type	Method and Description
void	registerKnownTableNames(java.util.List<TableName> tableNames) Register the table names as extracted from the FROM clause.

Methods inherited from interface org.apache.beam.sdk.extensions.sql.meta.provider.TableProvider

buildBeamSqlTable, createTable, dropTable, getSubProvider, getSubProviders, getTable, getTables, getTableType

Method Detail

registerKnownTableNames

void registerKnownTableNames(java.util.List<TableName> tableNames)

Register the table names as extracted from the FROM clause.

Calcite doesn't provide these full names to table providers and queries them with individual parts of the identifiers without giving any extra context. So if a table provider needs to implement some custom table name resolution strategy it doesn't have information to do so. E.g. if you want to take the compound SQL identifiers that were originally split by dots, join them into a single string, and then query a back-end service, this interface makes this possible.