This impacts the Grafana plugin.

From https://github.com/grafana/clickhouse-datasource/issues/198


    if an adhoc filter is specified for the field t1_distributed.f2
        the following query will be built by the plugin SELECT f1 from t1_distributed settings additional_table_filters = {'t1_distributed': 'f2 = xxx'}
        this query will actually not do its job of filtering
        i guess it is coming from the fact that additional_table_filters are applied by clickhouse when it reads the table....but distributed tables are not read.....
        if i replace in the built query, within the additional_table_filters settings, t1_distributed with t1_local (so a query like `SELECT f1 from t1_distributed settings additional_table_filters = {'t1_local': 'f2 = xxx'}), then it is working as expected
    i gave a try to add an adhoc filter on the "local" table (while my "main" query is still on the distributed table) (ie define an adhoc filter on the fied t1_local.f2)
        then the built query by the plugin does not include any additional_table_filters settings (i guess there is a check in order to add additional_table_filters only on the table used in the query)




using ExpressionActionsPtr = std::shared_ptr<ExpressionActions>;
struct StorageID;
namespace ClusterProxy
{
class SelectStreamFactory;
ContextMutablePtr updateSettingsForCluster(
    const Cluster & cluster, ContextPtr context, const Settings & settings, Poco::Logger * log = nullptr);
void executeQuery(
    QueryPlan & query_plan,
    const Block & header,
    QueryProcessingStage::Enum processed_stage,
    const StorageID & main_table,
    const ASTPtr & table_func_ptr,
    SelectStreamFactory & stream_factory, Poco::Logger * log,
    const ASTPtr & query_ast, ContextPtr context, const SelectQueryInfo & query_info,
    const ExpressionActionsPtr & sharding_key_expr,
    const std::string & sharding_key_column_name,
    const ClusterPtr & not_optimized_cluster);
void executeQueryWithParallelReplicas(
    QueryPlan & query_plan,
    const StorageID & main_table,
    const ASTPtr & table_func_ptr,
    SelectStreamFactory & stream_factory,
    const ASTPtr & query_ast, ContextPtr context, const SelectQueryInfo & query_info,
    const ExpressionActionsPtr & sharding_key_expr,
    const std::string & sharding_key_column_name,
    const ClusterPtr & not_optimized_cluster);
}
}