Performance Optimization

# Production JVM flags for CIA platform (Java 21+)
JAVA_OPTS="-server \
  -Xms2g -Xmx4g \
  -XX:+UseG1GC \
  -XX:MaxGCPauseMillis=200 \
  -XX:+UseStringDeduplication \
  -XX:+OptimizeStringConcat \
  -XX:MetaspaceSize=256m \
  -XX:MaxMetaspaceSize=512m \
  -XX:+HeapDumpOnOutOfMemoryError \
  -XX:HeapDumpPath=/var/log/cia/heapdump.hprof \
  -Djava.security.egd=file:/dev/./urandom"

// ✅ EFFICIENT: Stream processing for large datasets
@Service
public class VotingDataProcessor {

    @Transactional(readOnly = true)
    public void processVotingRecords(String sessionId) {
        try (Stream<VoteData> votes = voteRepository.streamBySession(sessionId)) {
            votes.map(this::analyzeVote)
                 .filter(Objects::nonNull)
                 .forEach(resultRepository::save);
        }
        // Stream auto-closes, no memory accumulation
    }
}

// ❌ INEFFICIENT: Loading all records into memory
public void processVotingRecords(String sessionId) {
    List<VoteData> allVotes = voteRepository.findBySession(sessionId);
    // May load millions of records into heap
}

-- High-impact indexes for common CIA queries
-- Politician lookup by party and status
CREATE INDEX idx_person_party_status
  ON person_data (party, status) WHERE status = 'ACTIVE';

-- Voting record time-series queries
CREATE INDEX idx_vote_date_committee
  ON vote_data (vote_date DESC, committee_id);

-- Document search optimization
CREATE INDEX idx_document_search
  ON document_content USING gin(to_tsvector('swedish', content));

-- Materialized view refresh tracking
CREATE INDEX idx_mv_refresh_status
  ON materialized_view_log (view_name, last_refresh DESC);

// ❌ N+1 Query Problem
@Entity
public class Committee {
    @OneToMany(fetch = FetchType.LAZY)
    private List<CommitteeMember> members;
}
// Accessing committee.getMembers() in a loop = N+1 queries

// ✅ FIX: Use JOIN FETCH or EntityGraph
@Query("SELECT c FROM Committee c JOIN FETCH c.members WHERE c.id = :id")
Committee findWithMembers(@Param("id") Long id);

// ✅ FIX: Use @EntityGraph
@EntityGraph(attributePaths = {"members", "members.person"})
Committee findById(Long id);

-- Concurrent refresh to avoid locks during read
REFRESH MATERIALIZED VIEW CONCURRENTLY view_riksdagen_politician_summary;

-- Schedule refresh based on data freshness requirements
-- High priority: refresh every 15 minutes during business hours
-- Low priority: refresh daily during off-peak

// ✅ EFFICIENT: Lazy loading with DataProvider
Grid<PoliticianSummary> grid = new Grid<>(PoliticianSummary.class);
grid.setDataProvider(
    DataProvider.fromCallbacks(
        query -> politicianService.fetch(query.getOffset(), query.getLimit()),
        query -> politicianService.count()
    )
);

// ❌ INEFFICIENT: Loading all items upfront
grid.setItems(politicianService.findAll()); // Loads everything

// ✅ Use virtual scrolling for long lists
grid.setPageSize(50);
grid.setMultiSort(true);

// ✅ Minimize push updates
@Push(transport = Transport.WEBSOCKET_XHR)
public class MainView extends AppLayout {
    // Only push critical real-time updates
}

// ✅ Defer non-critical UI updates
UI.getCurrent().access(() -> {
    notificationComponent.update(newData);
});

@Service
public class PoliticianService {

    // Cache frequently accessed, rarely changing data
    @Cacheable(value = "politicians", key = "#personId",
               unless = "#result == null")
    public PoliticianSummary getPolitician(String personId) {
        return repository.findSummaryById(personId);
    }

    // Evict cache when data is updated
    @CacheEvict(value = "politicians", key = "#personId")
    public void updatePolitician(String personId, PoliticianUpdate update) {
        repository.update(personId, update);
    }
}

// ✅ Read-only transactions for queries (no dirty checking)
@Transactional(readOnly = true)
public List<VotingSummary> getVotingSummaries(String sessionId) {
    return votingRepository.findSummariesBySession(sessionId);
}

// ✅ Batch operations for bulk inserts
@Transactional
public void importVotingData(List<VoteData> votes) {
    int batchSize = 50;
    for (int i = 0; i < votes.size(); i++) {
        entityManager.persist(votes.get(i));
        if (i % batchSize == 0) {
            entityManager.flush();
            entityManager.clear(); // Release memory
        }
    }
}

@BenchmarkMode(Mode.AverageTime)
@OutputTimeUnit(TimeUnit.MILLISECONDS)
@State(Scope.Benchmark)
public class PoliticianLookupBenchmark {

    @Benchmark
    public void benchmarkPoliticianSearch() {
        politicianService.searchByName("test");
    }
}