ClickHouse/src/Storages/IStorageCluster.h

#pragma once

#include <Storages/IStorage.h>
#include <Interpreters/Cluster.h>
#include <QueryPipeline/RemoteQueryExecutor.h>

namespace DB
{


/**
 *  Base cluster for Storages used in table functions like s3Cluster and hdfsCluster
 *  Needed for code simplification around parallel_distributed_insert_select
 */
class IStorageCluster : public IStorage
{
public:

    explicit IStorageCluster(const StorageID & table_id_) : IStorage(table_id_) {}

    virtual ClusterPtr getCluster(ContextPtr context) const = 0;
    /// Query is needed for pruning by virtual columns (_file, _path)
    virtual RemoteQueryExecutor::Extension getTaskIteratorExtension(ASTPtr query, ContextPtr context) const = 0;

    bool isRemote() const override { return true; }

    static ContextPtr updateSettingsForTableFunctionCluster(ContextPtr context, const Settings & settings)
    {
        Settings new_settings = settings;

        /// Cluster table functions should always skip unavailable shards.
        new_settings.skip_unavailable_shards = true;

        auto new_context = Context::createCopy(context);
        new_context->setSettings(new_settings);
        return new_context;
    }
};


}