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Refactor TANE-based algorithms
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Generalize Tane and PFDTane algorithms,
remove AUCC discovery and perform
additional pruning.
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Ilia committed Mar 22, 2024
1 parent 82d6c2b commit 9b3495c
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Showing 7 changed files with 352 additions and 561 deletions.
265 changes: 16 additions & 249 deletions src/core/algorithms/fd/pfdtane/pfdtane.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -24,7 +24,12 @@ namespace algos {
using boost::dynamic_bitset;
using Cluster = model::PositionListIndex::Cluster;

config::ErrorType PFDTane::CalculateZeroAryFdError(ColumnData const* rhs) {
PFDTane::PFDTane() : TaneCommon() {
RegisterOptions();
}

config::ErrorType PFDTane::CalculateZeroAryFdError(ColumnData const* rhs,
ColumnLayoutRelationData const*) {
std::size_t max = 1;
model::PositionListIndex const* x_pli = rhs->GetPositionListIndex();
for (Cluster const& x_cluster : x_pli->GetIndex()) {
Expand All @@ -35,7 +40,7 @@ config::ErrorType PFDTane::CalculateZeroAryFdError(ColumnData const* rhs) {

config::ErrorType PFDTane::CalculateFdError(model::PositionListIndex const* x_pli,
model::PositionListIndex const* xa_pli,
ErrorMeasure measure) {
ErrorMeasure measure, ColumnLayoutRelationData const*) {
std::deque<Cluster> xa_index = xa_pli->GetIndex();
std::shared_ptr<Cluster const> probing_table = x_pli->CalculateAndGetProbingTable();
std::sort(xa_index.begin(), xa_index.end(),
Expand Down Expand Up @@ -70,6 +75,15 @@ config::ErrorType PFDTane::CalculateFdError(model::PositionListIndex const* x_pl
return 1.0 - probability;
}

config::ErrorType PFDTane::CalculateZeroAryFdError(ColumnData const* rhs) {
return CalculateZeroAryFdError(rhs, relation_.get());
}

config::ErrorType PFDTane::CalculateFdError(model::PositionListIndex const* lhs_pli,
model::PositionListIndex const* joint_pli) {
return CalculateFdError(lhs_pli, joint_pli, error_measure_, relation_.get());
}

void PFDTane::RegisterOptions() {
RegisterOption(config::ErrorOpt(&max_ucc_error_));
RegisterOption(config::ErrorMeasureOpt(&error_measure_));
Expand All @@ -81,251 +95,4 @@ void PFDTane::MakeExecuteOptsAvailable() {
config::MaxLhsOpt.GetName()});
}

void PFDTane::ResetStateFd() {}

PFDTane::PFDTane() : PliBasedFDAlgorithm({kDefaultPhaseName}) {
RegisterOptions();
}

double PFDTane::CalculateUccError(model::PositionListIndex const* pli,
ColumnLayoutRelationData const* relation_data) {
return pli->GetNepAsLong() / static_cast<double>(relation_data->GetNumTuplePairs());
}

void PFDTane::RegisterAndCountFd(Vertical const& lhs, Column const* rhs,
[[maybe_unused]] config::ErrorType error,
[[maybe_unused]] RelationalSchema const* schema) {
dynamic_bitset<> lhs_bitset = lhs.GetColumnIndices();
PliBasedFDAlgorithm::RegisterFd(lhs, *rhs);
}

void PFDTane::Prune(model::LatticeLevel* level) {
RelationalSchema const* schema = relation_->GetSchema();
std::list<model::LatticeVertex*> key_vertices;
for (auto& [map_key, vertex] : level->GetVertices()) {
Vertical columns = vertex->GetVertical(); // Originally it's a ColumnCombination

if (vertex->GetIsKeyCandidate()) {
double ucc_error = CalculateUccError(vertex->GetPositionListIndex(), relation_.get());
if (ucc_error <= max_ucc_error_) { // If a key candidate is an approx UCC
// TODO: do smth with UCC

vertex->SetKeyCandidate(false);
if (ucc_error == 0) {
for (std::size_t rhs_index = vertex->GetRhsCandidates().find_first();
rhs_index != boost::dynamic_bitset<>::npos;
rhs_index = vertex->GetRhsCandidates().find_next(rhs_index)) {
Vertical rhs = static_cast<Vertical>(*schema->GetColumn((int)rhs_index));
if (!columns.Contains(rhs)) {
bool is_rhs_candidate = true;
for (auto const& column : columns.GetColumns()) {
Vertical sibling =
columns.Without(static_cast<Vertical>(*column)).Union(rhs);
auto sibling_vertex =
level->GetLatticeVertex(sibling.GetColumnIndices());
if (sibling_vertex == nullptr ||
!sibling_vertex->GetConstRhsCandidates()
[rhs.GetColumnIndices().find_first()]) {
is_rhs_candidate = false;
break;
}
// for each outer rhs: if there is a sibling s.t. it doesn't
// have this rhs, there is no FD: vertex->rhs
}
// Found fd: vertex->rhs => register it
if (is_rhs_candidate) {
RegisterAndCountFd(columns, schema->GetColumn(rhs_index), 0,
schema);
}
}
}
key_vertices.push_back(vertex.get());
// cout << "--------------------------" << endl << "KeyVert: " << *vertex;
}
}
}
// if we seek for exact FDs then SetInvalid
if (max_fd_error_ == 0 && max_ucc_error_ == 0) {
for (auto key_vertex : key_vertices) {
key_vertex->GetRhsCandidates() &= key_vertex->GetVertical().GetColumnIndices();
key_vertex->SetInvalid(true);
}
}
}
}

void PFDTane::ComputeDependencies(model::LatticeLevel* level) {
RelationalSchema const* schema = relation_->GetSchema();
for (auto& [key_map, xa_vertex] : level->GetVertices()) {
if (xa_vertex->GetIsInvalid()) {
continue;
}
Vertical xa = xa_vertex->GetVertical();
// Calculate XA PLI
if (xa_vertex->GetPositionListIndex() == nullptr) {
auto parent_pli_1 = xa_vertex->GetParents()[0]->GetPositionListIndex();
auto parent_pli_2 = xa_vertex->GetParents()[1]->GetPositionListIndex();
xa_vertex->AcquirePositionListIndex(parent_pli_1->Intersect(parent_pli_2));
}

dynamic_bitset<> xa_indices = xa.GetColumnIndices();
dynamic_bitset<> a_candidates = xa_vertex->GetRhsCandidates();
auto xa_pli = xa_vertex->GetPositionListIndex();
for (auto const& x_vertex : xa_vertex->GetParents()) {
Vertical const& lhs = x_vertex->GetVertical();

// Find index of A in XA. If a is not a candidate, continue. TODO: possible to do it
// easier??
// like "a_index = xa_indices - x_indices;"
int a_index = xa_indices.find_first();
dynamic_bitset<> x_indices = lhs.GetColumnIndices();
while (a_index >= 0 && x_indices[a_index]) {
a_index = xa_indices.find_next(a_index);
}
if (!a_candidates[a_index]) {
continue;
}
auto x_pli = x_vertex->GetPositionListIndex();

// Check X -> A
config::ErrorType error = CalculateFdError(x_pli, xa_pli, error_measure_);
if (error <= max_fd_error_) {
Column const* rhs = schema->GetColumns()[a_index].get();

RegisterAndCountFd(lhs, rhs, error, schema);
xa_vertex->GetRhsCandidates().set(rhs->GetIndex(), false);
if (error == 0) {
xa_vertex->GetRhsCandidates() &= lhs.GetColumnIndices();
}
}
}
}
}

unsigned long long PFDTane::ExecuteInternal() {
long apriori_millis_ = 0;
max_fd_error_ = max_ucc_error_;
RelationalSchema const* schema = relation_->GetSchema();

LOG(DEBUG) << schema->GetName() << " has " << relation_->GetNumColumns() << " columns, "
<< relation_->GetNumRows() << " rows, and a maximum NIP of " << std::setw(2)
<< relation_->GetMaximumNip() << ".";

for (auto& column : schema->GetColumns()) {
double avg_partners = relation_->GetColumnData(column->GetIndex())
.GetPositionListIndex()
->GetNepAsLong() *
2.0 / relation_->GetNumRows();
LOG(DEBUG) << "* " << column->ToString() << ": every tuple has " << std::setw(2)
<< avg_partners << " partners on average.";
}
auto start_time = std::chrono::system_clock::now();
double progress_step = 100.0 / (schema->GetNumColumns() + 1);

// Initialize level 0
std::vector<std::unique_ptr<model::LatticeLevel>> levels;
auto level0 = std::make_unique<model::LatticeLevel>(0);
// TODO: через указатели кажется надо переделать
level0->Add(std::make_unique<model::LatticeVertex>(*(schema->empty_vertical_)));
model::LatticeVertex const* empty_vertex = level0->GetVertices().begin()->second.get();
levels.push_back(std::move(level0));
AddProgress(progress_step);

// Initialize level1
dynamic_bitset<> zeroary_fd_rhs(schema->GetNumColumns());
auto level1 = std::make_unique<model::LatticeLevel>(1);
for (auto& column : schema->GetColumns()) {
// for each attribute set vertex
ColumnData const& column_data = relation_->GetColumnData(column->GetIndex());
auto vertex = std::make_unique<model::LatticeVertex>(static_cast<Vertical>(*column));

vertex->AddRhsCandidates(schema->GetColumns());
vertex->GetParents().push_back(empty_vertex);
vertex->SetKeyCandidate(true);
vertex->SetPositionListIndex(column_data.GetPositionListIndex());

// check FDs: 0->A
double fd_error = CalculateZeroAryFdError(&column_data);
if (fd_error <= max_fd_error_) { // TODO: max_error
zeroary_fd_rhs.set(column->GetIndex());
RegisterAndCountFd(*schema->empty_vertical_, column.get(), fd_error, schema);

vertex->GetRhsCandidates().set(column->GetIndex(), false);
if (fd_error == 0) {
vertex->GetRhsCandidates().reset();
}
}

level1->Add(std::move(vertex));
}

for (auto& [key_map, vertex] : level1->GetVertices()) {
Vertical column = vertex->GetVertical();
vertex->GetRhsCandidates() &=
~zeroary_fd_rhs; //~ returns flipped copy <- removed already discovered zeroary FDs

// вот тут костыль, чтобы вытянуть индекс колонки из вершины, в которой только один индекс
ColumnData const& column_data =
relation_->GetColumnData(column.GetColumnIndices().find_first());
double ucc_error = CalculateUccError(column_data.GetPositionListIndex(), relation_.get());
if (ucc_error <= max_ucc_error_) {
vertex->SetKeyCandidate(false);
if (ucc_error == 0 && max_lhs_ != 0) {
for (unsigned long rhs_index = vertex->GetRhsCandidates().find_first();
rhs_index < vertex->GetRhsCandidates().size();
rhs_index = vertex->GetRhsCandidates().find_next(rhs_index)) {
if (rhs_index != column.GetColumnIndices().find_first()) {
RegisterAndCountFd(column, schema->GetColumn(rhs_index), 0, schema);
}
}
vertex->GetRhsCandidates() &= column.GetColumnIndices();
// set vertex invalid if we seek for exact dependencies
if (max_fd_error_ == 0 && max_ucc_error_ == 0) {
vertex->SetInvalid(true);
}
}
}
}
levels.push_back(std::move(level1));
AddProgress(progress_step);

unsigned int max_arity =
max_lhs_ == std::numeric_limits<unsigned int>::max() ? max_lhs_ : max_lhs_ + 1;
for (unsigned int arity = 2; arity <= max_arity; arity++) {
model::LatticeLevel::ClearLevelsBelow(levels, arity - 1);
model::LatticeLevel::GenerateNextLevel(levels);

model::LatticeLevel* level = levels[arity].get();
LOG(TRACE) << "Checking " << level->GetVertices().size() << " " << arity
<< "-ary lattice vertices.";
if (level->GetVertices().empty()) {
break;
}

ComputeDependencies(level);

if (arity == max_arity) {
break;
}

Prune(level);
// TODO: printProfilingData
AddProgress(progress_step);
}

SetProgress(100);
std::chrono::milliseconds elapsed_milliseconds =
std::chrono::duration_cast<std::chrono::milliseconds>(std::chrono::system_clock::now() -
start_time);
apriori_millis_ += elapsed_milliseconds.count();

LOG(DEBUG) << "Time: " << apriori_millis_ << " milliseconds";
LOG(DEBUG) << "Intersection time: " << model::PositionListIndex::micros_ / 1000 << "ms";
LOG(DEBUG) << "Total intersections: " << model::PositionListIndex::intersection_count_
<< std::endl;
LOG(DEBUG) << "Total FD count: " << fd_collection_.Size();
LOG(DEBUG) << "HASH: " << Fletcher16();
return apriori_millis_;
}

} // namespace algos
25 changes: 9 additions & 16 deletions src/core/algorithms/fd/pfdtane/pfdtane.h
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Original file line number Diff line number Diff line change
Expand Up @@ -2,6 +2,7 @@

#include "algorithms/fd/pli_based_fd_algorithm.h"
#include "algorithms/fd/tane/lattice_level.h"
#include "algorithms/fd/tane/tane_common.h"
#include "config/error/type.h"
#include "config/error_measure/type.h"
#include "config/max_lhs/type.h"
Expand All @@ -11,31 +12,23 @@

namespace algos {

class PFDTane : public PliBasedFDAlgorithm {
class PFDTane : public TaneCommon {
private:
config::ErrorType max_fd_error_;
config::ErrorType max_ucc_error_;
config::MaxLhsType max_lhs_;
ErrorMeasure error_measure_ = +ErrorMeasure::per_tuple;

void ResetStateFd() final;
void RegisterOptions();
void MakeExecuteOptsAvailable() final;
void Prune(model::LatticeLevel* level);
void ComputeDependencies(model::LatticeLevel* level);
unsigned long long ExecuteInternal() final;
config::ErrorType CalculateZeroAryFdError(ColumnData const* rhs) override;
config::ErrorType CalculateFdError(model::PositionListIndex const* lhs_pli,
model::PositionListIndex const* joint_pli) override;

public:
PFDTane();
static double CalculateUccError(model::PositionListIndex const* pli,
ColumnLayoutRelationData const* relation_data);

void RegisterAndCountFd(Vertical const& lhs, Column const* rhs, double error,
RelationalSchema const* schema);
static config::ErrorType CalculateZeroAryFdError(ColumnData const* rhs);
static config::ErrorType CalculateZeroAryFdError(ColumnData const* rhs,
ColumnLayoutRelationData const* relation_data);
static config::ErrorType CalculateFdError(model::PositionListIndex const* x_pli,
model::PositionListIndex const* xa_pli,
ErrorMeasure error_measure);
ErrorMeasure error_measure,
ColumnLayoutRelationData const* relation_data);
};

} // namespace algos
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