Method joinedTableOrFunction

src/Client/BuzzHouse/Generator/SQLQuery.cpp:733–1314

StatementGenerator::FromSourceInfo StatementGenerator::joinedTableOrFunction(
    RandomGenerator & rg, const String & rel_name, const uint32_t allowed_clauses, const bool under_remote, TableOrFunction * tof)
{
    const SQLTable * t = nullptr;
    const SQLView * v = nullptr;

    const auto has_table_lambda = getQueryTableLambda<TableRequirement::NoRequirement>();
    const auto has_mergetree_table_lambda = getQueryTableLambda<TableRequirement::RequireMergeTree>();
    const auto has_replaceable_table_lambda = getQueryTableLambda<TableRequirement::RequireReplaceable>();
    const auto has_view_lambda
        = [&](const SQLView & vv) { return vv.isAttached() && (vv.is_deterministic || this->allow_not_deterministic); };
    const auto has_dictionary_lambda
        = [&](const SQLDictionary & d) { return d.isAttached() && (d.is_deterministic || this->allow_not_deterministic); };

    const bool has_table = collectionHas<SQLTable>(has_table_lambda);
    const bool has_mergetree_table = collectionHas<SQLTable>(has_mergetree_table_lambda);
    const bool has_replaceable_table = collectionHas<SQLTable>(has_replaceable_table_lambda);
    const bool has_view = collectionHas<SQLView>(has_view_lambda);
    const bool has_dictionary = collectionHas<SQLDictionary>(has_dictionary_lambda);
    const bool can_recurse = this->depth < this->fc.max_depth && this->width < this->fc.max_width;

    /// queryMask[static_cast<size_t>(QueryOp::DerivatedTable)] = true;
    queryMask[static_cast<size_t>(QueryOp::CTE)] = !under_remote && !this->ctes.empty();
    queryMask[static_cast<size_t>(QueryOp::Table)] = has_table;
    queryMask[static_cast<size_t>(QueryOp::View)] = this->peer_query != PeerQuery::ClickHouseOnly && has_view;
    queryMask[static_cast<size_t>(QueryOp::RemoteUDF)] = !under_remote && this->allow_engine_udf && can_recurse;
    /// queryMask[static_cast<size_t>(QueryOp::NumbersUDF)] = true;
    queryMask[static_cast<size_t>(QueryOp::SystemTable)] = this->allow_not_deterministic && !systemTables.empty();
    queryMask[static_cast<size_t>(QueryOp::MergeUDF)] = this->allow_engine_udf;
    queryMask[static_cast<size_t>(QueryOp::ClusterUDF)] = !under_remote && this->allow_engine_udf && !fc.clusters.empty() && can_recurse;
    queryMask[static_cast<size_t>(QueryOp::LoopUDF)] = fc.allow_infinite_tables && this->allow_engine_udf && can_recurse;
    /// queryMask[static_cast<size_t>(QueryOp::ValuesUDF)] = true;
    queryMask[static_cast<size_t>(QueryOp::RandomDataUDF)] = this->allow_engine_udf;
    queryMask[static_cast<size_t>(QueryOp::Dictionary)] = this->peer_query != PeerQuery::ClickHouseOnly && has_dictionary;
    queryMask[static_cast<size_t>(QueryOp::URLEncodedTable)] = this->allow_engine_udf && has_table;
    queryMask[static_cast<size_t>(QueryOp::TableEngineUDF)] = has_replaceable_table && this->allow_engine_udf;
    queryMask[static_cast<size_t>(QueryOp::RandomTableUDF)] = this->allow_not_deterministic && this->allow_engine_udf;
    queryMask[static_cast<size_t>(QueryOp::MergeIndexUDF)] = has_mergetree_table && this->allow_engine_udf;
    queryMask[static_cast<size_t>(QueryOp::MergeProjectionUDF)] = has_mergetree_table && this->allow_engine_udf;
    queryMask[static_cast<size_t>(QueryOp::MergeTextIndexUDF)] = has_mergetree_table && this->allow_engine_udf;
    queryMask[static_cast<size_t>(QueryOp::MergeIndexAnalyzeUDF)] = has_mergetree_table && this->allow_engine_udf;
    /// `filesystem([path])` reads local files (metadata + optional content) — non-deterministic
    /// and needs FILE access. Don't emit it through `remote()` either.
    queryMask[static_cast<size_t>(QueryOp::FilesystemUDF)] = !under_remote && this->allow_not_deterministic && this->allow_engine_udf;

    queryGen.setEnabled(queryMask);
    /// If MV chaining is requested, force the next source to be a view (clears flag after use)
    const bool chain_views_now = this->chain_views;
    this->chain_views = false;
    const auto nopt = (chain_views_now && queryMask[static_cast<size_t>(QueryOp::View)] && rg.nextBool())
        ? QueryOp::View
        : static_cast<QueryOp>(queryGen.nextOp()); /// drifts over time

    switch (nopt)
    {
        case QueryOp::DerivatedTable: {
            /// A derived query
            SQLRelation rel(rel_name);