Method getTablesForBackup

src/Databases/DatabaseMemory.cpp:188–238

}

std::vector<std::pair<ASTPtr, StoragePtr>> DatabaseMemory::getTablesForBackup(const FilterByNameFunction & filter, const ContextPtr & local_context) const
{
    /// We need a special processing for the temporary database.
    if (getDatabaseName() != DatabaseCatalog::TEMPORARY_DATABASE)
        return DatabaseWithOwnTablesBase::getTablesForBackup(filter, local_context);

    std::vector<std::pair<ASTPtr, StoragePtr>> res;

    /// `this->tables` for the temporary database doesn't contain real names of tables.
    /// That's why we need to call Context::getExternalTables() and then resolve those names using tryResolveStorageID() below.
    auto external_tables = local_context->getExternalTables();

    for (const auto & [table_name, storage] : external_tables)
    {
        if (!filter(table_name))
            continue;

        auto storage_id = local_context->tryResolveStorageID(StorageID{"", table_name}, Context::ResolveExternal);
        if (!storage_id)
        {
            LOG_WARNING(log, "Couldn't resolve the name of temporary table {}", backQuoteIfNeed(table_name));
            continue;
        }

        /// Here `storage_id.table_name` looks like looks like "_tmp_ab9b15a3-fb43-4670-abec-14a0e9eb70f1"
        /// it's not the real name of the table.
        auto create_table_query = tryGetCreateTableQuery(storage_id.table_name, local_context);
        if (!create_table_query)
        {
            LOG_WARNING(log, "Couldn't get a create query for temporary table {}", backQuoteIfNeed(table_name));
            continue;
        }

        auto * create = create_table_query->as<ASTCreateQuery>();
        if (create->getTable() != table_name)
        {
            /// Probably the database has been just renamed. Use the older name for backup to keep the backup consistent.
            LOG_WARNING(log, "Got a create query with unexpected name {} for temporary table {}",
                        backQuoteIfNeed(create->getTable()), backQuoteIfNeed(table_name));
            create_table_query = create_table_query->clone();
            create = create_table_query->as<ASTCreateQuery>();
            create->setTable(table_name);
        }

        chassert(storage);
        storage->applyMetadataChangesToCreateQueryForBackup(create_table_query);
        res.emplace_back(create_table_query, storage);
    }

    return res;
}

void registerDatabaseMemory(DatabaseFactory & factory);
void registerDatabaseMemory(DatabaseFactory & factory)