/**
* AddSamplesTable - Add a samples table into the 'samples_db'.
* The table name is generated by concatenating db_id and table_id with '_'.
*/
void TupleSamplesStorage::AddSamplesTable(
storage::DataTable *data_table,
std::vector<std::unique_ptr<storage::Tuple>> &sampled_tuples) {
auto schema = data_table->GetSchema();
auto schema_copy = catalog::Schema::CopySchema(schema);
std::unique_ptr<catalog::Schema> schema_ptr(schema_copy);
auto catalog = catalog::Catalog::GetInstance();
bool is_catalog = false;
std::string samples_table_name = GenerateSamplesTableName(
data_table->GetDatabaseOid(), data_table->GetOid());
auto &txn_manager = concurrency::TransactionManagerFactory::GetInstance();
auto txn = txn_manager.BeginTransaction();
catalog->CreateTable(std::string(SAMPLES_DB_NAME),
std::string(DEFAULT_SCHEMA_NAME), samples_table_name,
std::move(schema_ptr), txn, is_catalog);
auto samples_table = catalog->GetTableWithName(
std::string(SAMPLES_DB_NAME), std::string(DEFAULT_SCHEMA_NAME),
samples_table_name, txn);
for (auto &tuple : sampled_tuples) {
InsertSampleTuple(samples_table, std::move(tuple), txn);
}
txn_manager.CommitTransaction(txn);
}
void OperatorToPlanTransformer::Visit(const PhysicalProject *) {
auto project_prop = requirements_->GetPropertyOfType(PropertyType::PROJECT)
->As<PropertyProjection>();
(void)project_prop;
size_t project_list_size = project_prop->GetProjectionListSize();
// expressions to evaluate
TargetList tl = TargetList();
// columns which can be returned directly
DirectMapList dml = DirectMapList();
// schema of the projections output
std::vector<catalog::Column> columns;
for (size_t project_idx = 0; project_idx < project_list_size; project_idx++) {
auto expr = project_prop->GetProjection(project_idx);
std::string column_name;
// if the root of the expression is a column value we can
// just do a direct mapping
if (expr->GetExpressionType() == ExpressionType::VALUE_TUPLE) {
auto tup_expr = (expression::TupleValueExpression *)expr;
column_name = tup_expr->GetColumnName();
dml.push_back(
DirectMap(project_idx, std::make_pair(0, tup_expr->GetColumnId())));
}
// otherwise we need to evaluat the expression
else {
column_name = "expr" + std::to_string(project_idx);
tl.push_back(Target(project_idx, expr->Copy()));
}
columns.push_back(catalog::Column(
expr->GetValueType(), type::Type::GetTypeSize(expr->GetValueType()),
column_name));
}
// build the projection plan node and insert aboce the scan
std::unique_ptr<planner::ProjectInfo> proj_info(
new planner::ProjectInfo(std::move(tl), std::move(dml)));
std::shared_ptr<catalog::Schema> schema_ptr(new catalog::Schema(columns));
std::unique_ptr<planner::AbstractPlan> project_plan(
new planner::ProjectionPlan(std::move(proj_info), schema_ptr));
output_plan_ = std::move(project_plan);
}
