const std::string Layout::GetInfo() const {
std::ostringstream os;
os << peloton::GETINFO_DOUBLE_STAR << " Layout[#" << layout_oid_ << "] "
<< peloton::GETINFO_DOUBLE_STAR << std::endl;
os << "Number of columns[" << num_columns_ << "] " << std::endl;
os << "LayoutType[" << LayoutTypeToString(layout_type_) << std::endl;
os << "ColumnMap[ " << GetColumnMapInfo() << "] " << std::endl;
return peloton::StringUtil::Prefix(peloton::StringBoxUtil::Box(os.str()),
GETINFO_SPACER);
}
TEST_F(LayoutTunerTests, BasicTest) {
const int tuple_count = TESTS_TUPLES_PER_TILEGROUP;
std::string db_name = "test_db";
TestingExecutorUtil::InitializeDatabase(db_name);
auto data_table =
TestingExecutorUtil::CreateTableUpdateCatalog(tuple_count, db_name);
// Create a table and populate it
auto &txn_manager = concurrency::TransactionManagerFactory::GetInstance();
auto txn = txn_manager.BeginTransaction();
TestingExecutorUtil::PopulateTable(data_table, tuple_count, false, false,
true, txn);
txn_manager.CommitTransaction(txn);
// Check column count
oid_t column_count = data_table->GetSchema()->GetColumnCount();
EXPECT_EQ(column_count, 4);
// Layout tuner
tuning::LayoutTuner &layout_tuner = tuning::LayoutTuner::GetInstance();
// Attach table to index tuner
layout_tuner.AddTable(data_table);
// Check old default tile group layout
auto old_default_layout = data_table->GetDefaultLayout();
LOG_INFO("Layout: %s", old_default_layout->GetColumnMapInfo().c_str());
// Start layout tuner
layout_tuner.Start();
std::vector<double> columns_accessed(column_count, 0);
double sample_weight;
// initialize a uniform distribution between 0 and 1
UniformGenerator generator;
for (int sample_itr = 0; sample_itr < 10000; sample_itr++) {
auto rng_val = generator.GetSample();
if (rng_val < 0.9) {
columns_accessed = {0, 1, 2};
sample_weight = 100;
}
else {
columns_accessed = {3};
sample_weight = 10;
}
// Create a table access sample
// Indicates the columns accessed (bitmap), and query weight
tuning::Sample sample(columns_accessed, sample_weight);
// Collect layout sample in table
data_table->RecordLayoutSample(sample);
// Periodically sleep a bit
// Layout tuner thread will process the layout samples periodically,
// derive the new table layout, and
// transform the layout of existing tile groups in the table
if(sample_itr % 100 == 0 ){
std::this_thread::sleep_for(std::chrono::microseconds(1000));
}
}
// Stop layout tuner
layout_tuner.Stop();
// Detach all tables from layout tuner
layout_tuner.ClearTables();
// Check new default tile group layout
auto new_default_layout = data_table->GetDefaultLayout();
LOG_INFO("Layout: %s", new_default_layout->GetColumnMapInfo().c_str());
// Ensure that the layout has been changed
EXPECT_NE(*new_default_layout, *old_default_layout);
// Check the new default table layout
column_count = new_default_layout->GetColumnCount();
EXPECT_EQ(column_count, 4);
// Check the tile corresponding to each column.
EXPECT_EQ(new_default_layout->GetTileIdFromColumnId(0), 0);
EXPECT_EQ(new_default_layout->GetTileIdFromColumnId(1), 0);
EXPECT_EQ(new_default_layout->GetTileIdFromColumnId(2), 0);
EXPECT_EQ(new_default_layout->GetTileIdFromColumnId(3), 1);
// Check the per tile stats of the new layout
// The layout must contain 2 tiles with the following stats
// 0 -> 3
// 1 -> 1
auto layout_stats = new_default_layout->GetLayoutStats();
EXPECT_EQ(layout_stats[0], 3);
EXPECT_EQ(layout_stats[1], 1);
TestingExecutorUtil::DeleteDatabase(db_name);
}