fix: cluster restore database detection and TUI error display

- Fixed psql connection for database detection (always use -h flag)
- Use CombinedOutput() to capture stderr for better diagnostics
- Added existingDBError tracking in restore preview
- Show 'Unable to detect' instead of misleading 'None' when listing fails
- Disable cleanup toggle when database detection failed

bin/README.md

@@ -4,8 +4,8 @@ This directory contains pre-compiled binaries for the DB Backup Tool across mult
 
 ## Build Information
 - **Version**: 3.42.50
-- **Build Time**: 2026-01-17_06:48:35_UTC
-- **Git Commit**: dd1db84
+- **Build Time**: 2026-01-17_15:26:14_UTC
+- **Git Commit**: df1ab2f
 
 ## Recent Updates (v1.1.0)
 - ✅ Fixed TUI progress display with line-by-line output

cmd/restore.go

@@ -290,7 +290,7 @@ func init() {
 	restoreClusterCmd.Flags().BoolVar(&restoreForce, "force", false, "Skip safety checks and confirmations")
 	restoreClusterCmd.Flags().BoolVar(&restoreCleanCluster, "clean-cluster", false, "Drop all existing user databases before restore (disaster recovery)")
 	restoreClusterCmd.Flags().IntVar(&restoreJobs, "jobs", 0, "Number of parallel decompression jobs (0 = auto)")
-	restoreClusterCmd.Flags().IntVar(&restoreParallelDBs, "parallel-dbs", 0, "Number of databases to restore in parallel (0 = use config default, 1 = sequential)")
+	restoreClusterCmd.Flags().IntVar(&restoreParallelDBs, "parallel-dbs", 0, "Number of databases to restore in parallel (0 = use config default, 1 = sequential, -1 = auto-detect based on CPU/RAM)")
 	restoreClusterCmd.Flags().StringVar(&restoreWorkdir, "workdir", "", "Working directory for extraction (use when system disk is small, e.g. /mnt/storage/restore_tmp)")
 	restoreClusterCmd.Flags().BoolVar(&restoreVerbose, "verbose", false, "Show detailed restore progress")
 	restoreClusterCmd.Flags().BoolVar(&restoreNoProgress, "no-progress", false, "Disable progress indicators")
@@ -786,7 +786,12 @@ func runRestoreCluster(cmd *cobra.Command, args []string) error {
 	}
 
 	// Override cluster parallelism if --parallel-dbs is specified
-	if restoreParallelDBs > 0 {
+	if restoreParallelDBs == -1 {
+		// Auto-detect optimal parallelism based on system resources
+		autoParallel := restore.CalculateOptimalParallel()
+		cfg.ClusterParallelism = autoParallel
+		log.Info("Auto-detected optimal parallelism for database restores", "parallel_dbs", autoParallel, "mode", "auto")
+	} else if restoreParallelDBs > 0 {
 		cfg.ClusterParallelism = restoreParallelDBs
 		log.Info("Using custom parallelism for database restores", "parallel_dbs", restoreParallelDBs)
 	}

internal/restore/preflight.go

@@ -16,6 +16,57 @@ import (
 	"github.com/shirou/gopsutil/v3/mem"
 )
 
+// CalculateOptimalParallel returns the recommended number of parallel workers
+// based on available system resources (CPU cores and RAM).
+// This is a standalone function that can be called from anywhere.
+// Returns 0 if resources cannot be detected.
+func CalculateOptimalParallel() int {
+	cpuCores := runtime.NumCPU()
+
+	vmem, err := mem.VirtualMemory()
+	if err != nil {
+		// Fallback: use half of CPU cores if memory detection fails
+		if cpuCores > 1 {
+			return cpuCores / 2
+		}
+		return 1
+	}
+
+	memAvailableGB := float64(vmem.Available) / (1024 * 1024 * 1024)
+
+	// Each pg_restore worker needs approximately 2-4GB of RAM
+	// Use conservative 3GB per worker to avoid OOM
+	const memPerWorkerGB = 3.0
+
+	// Calculate limits
+	maxByMem := int(memAvailableGB / memPerWorkerGB)
+	maxByCPU := cpuCores
+
+	// Use the minimum of memory and CPU limits
+	recommended := maxByMem
+	if maxByCPU < recommended {
+		recommended = maxByCPU
+	}
+
+	// Apply sensible bounds
+	if recommended < 1 {
+		recommended = 1
+	}
+	if recommended > 16 {
+		recommended = 16 // Cap at 16 to avoid diminishing returns
+	}
+
+	// If memory pressure is high (>80%), reduce parallelism
+	if vmem.UsedPercent > 80 && recommended > 1 {
+		recommended = recommended / 2
+		if recommended < 1 {
+			recommended = 1
+		}
+	}
+
+	return recommended
+}
+
 // PreflightResult contains all preflight check results
 type PreflightResult struct {
 	// Linux system checks
@@ -35,15 +86,17 @@ type PreflightResult struct {
 
 // LinuxChecks contains Linux kernel/system checks
 type LinuxChecks struct {
-	ShmMax         int64   // /proc/sys/kernel/shmmax
-	ShmAll         int64   // /proc/sys/kernel/shmall
-	MemTotal       uint64  // Total RAM in bytes
-	MemAvailable   uint64  // Available RAM in bytes
-	MemUsedPercent float64 // Memory usage percentage
-	ShmMaxOK       bool    // Is shmmax sufficient?
-	ShmAllOK       bool    // Is shmall sufficient?
-	MemAvailableOK bool    // Is available RAM sufficient?
-	IsLinux        bool    // Are we running on Linux?
+	ShmMax              int64   // /proc/sys/kernel/shmmax
+	ShmAll              int64   // /proc/sys/kernel/shmall
+	MemTotal            uint64  // Total RAM in bytes
+	MemAvailable        uint64  // Available RAM in bytes
+	MemUsedPercent      float64 // Memory usage percentage
+	CPUCores            int     // Number of CPU cores
+	RecommendedParallel int     // Auto-calculated optimal parallel count
+	ShmMaxOK            bool    // Is shmmax sufficient?
+	ShmAllOK            bool    // Is shmall sufficient?
+	MemAvailableOK      bool    // Is available RAM sufficient?
+	IsLinux             bool    // Are we running on Linux?
 }
 
 // PostgreSQLChecks contains PostgreSQL configuration checks
@@ -100,6 +153,7 @@ func (e *Engine) RunPreflightChecks(ctx context.Context, dumpsDir string, entrie
 // checkSystemResources uses gopsutil for cross-platform system checks
 func (e *Engine) checkSystemResources(result *PreflightResult) {
 	result.Linux.IsLinux = runtime.GOOS == "linux"
+	result.Linux.CPUCores = runtime.NumCPU()
 
 	// Get memory info (works on Linux, macOS, Windows, BSD)
 	if vmem, err := mem.VirtualMemory(); err == nil {
@@ -118,6 +172,9 @@ func (e *Engine) checkSystemResources(result *PreflightResult) {
 		e.log.Warn("Could not detect system memory", "error", err)
 	}
 
+	// Calculate recommended parallel based on resources
+	result.Linux.RecommendedParallel = e.calculateRecommendedParallel(result)
+
 	// Linux-specific kernel checks (shmmax, shmall)
 	if result.Linux.IsLinux {
 		e.checkLinuxKernel(result)
@@ -434,6 +491,56 @@ func (e *Engine) calculateRecommendations(result *PreflightResult) {
 		"recommended_locks", lockBoost)
 }
 
+// calculateRecommendedParallel determines optimal parallelism based on system resources
+// Returns the recommended number of parallel workers for pg_restore
+func (e *Engine) calculateRecommendedParallel(result *PreflightResult) int {
+	cpuCores := result.Linux.CPUCores
+	if cpuCores == 0 {
+		cpuCores = runtime.NumCPU()
+	}
+
+	memAvailableGB := float64(result.Linux.MemAvailable) / (1024 * 1024 * 1024)
+
+	// Each pg_restore worker needs approximately 2-4GB of RAM
+	// Use conservative 3GB per worker to avoid OOM
+	const memPerWorkerGB = 3.0
+
+	// Calculate limits
+	maxByMem := int(memAvailableGB / memPerWorkerGB)
+	maxByCPU := cpuCores
+
+	// Use the minimum of memory and CPU limits
+	recommended := maxByMem
+	if maxByCPU < recommended {
+		recommended = maxByCPU
+	}
+
+	// Apply sensible bounds
+	if recommended < 1 {
+		recommended = 1
+	}
+	if recommended > 16 {
+		recommended = 16 // Cap at 16 to avoid diminishing returns
+	}
+
+	// If memory pressure is high (>80%), reduce parallelism
+	if result.Linux.MemUsedPercent > 80 && recommended > 1 {
+		recommended = recommended / 2
+		if recommended < 1 {
+			recommended = 1
+		}
+	}
+
+	e.log.Info("Calculated recommended parallel",
+		"cpu_cores", cpuCores,
+		"mem_available_gb", fmt.Sprintf("%.1f", memAvailableGB),
+		"max_by_mem", maxByMem,
+		"max_by_cpu", maxByCPU,
+		"recommended", recommended)
+
+	return recommended
+}
+
 // printPreflightSummary prints a nice summary of all checks
 func (e *Engine) printPreflightSummary(result *PreflightResult) {
 	fmt.Println()
@@ -446,6 +553,8 @@ func (e *Engine) printPreflightSummary(result *PreflightResult) {
 	printCheck("Total RAM", humanize.Bytes(result.Linux.MemTotal), true)
 	printCheck("Available RAM", humanize.Bytes(result.Linux.MemAvailable), result.Linux.MemAvailableOK || result.Linux.MemAvailable == 0)
 	printCheck("Memory Usage", fmt.Sprintf("%.1f%%", result.Linux.MemUsedPercent), result.Linux.MemUsedPercent < 85)
+	printCheck("CPU Cores", fmt.Sprintf("%d", result.Linux.CPUCores), true)
+	printCheck("Recommended Parallel", fmt.Sprintf("%d (auto-calculated)", result.Linux.RecommendedParallel), true)
 
 	// Linux-specific kernel checks
 	if result.Linux.IsLinux && result.Linux.ShmMax > 0 {

internal/restore/safety.go

@@ -334,10 +334,12 @@ func (s *Safety) checkPostgresDatabaseExists(ctx context.Context, dbName string)
 		"-tAc", fmt.Sprintf("SELECT 1 FROM pg_database WHERE datname='%s'", dbName),
 	}
 
-	// Only add -h flag if host is not localhost (to use Unix socket for peer auth)
-	if s.cfg.Host != "localhost" && s.cfg.Host != "127.0.0.1" && s.cfg.Host != "" {
-		args = append([]string{"-h", s.cfg.Host}, args...)
+	// Always add -h flag for explicit host connection (required for password auth)
+	host := s.cfg.Host
+	if host == "" {
+		host = "localhost"
 	}
+	args = append([]string{"-h", host}, args...)
 
 	cmd := exec.CommandContext(ctx, "psql", args...)
 
@@ -346,9 +348,9 @@ func (s *Safety) checkPostgresDatabaseExists(ctx context.Context, dbName string)
 		cmd.Env = append(os.Environ(), fmt.Sprintf("PGPASSWORD=%s", s.cfg.Password))
 	}
 
-	output, err := cmd.Output()
+	output, err := cmd.CombinedOutput()
 	if err != nil {
-		return false, fmt.Errorf("failed to check database existence: %w", err)
+		return false, fmt.Errorf("failed to check database existence: %w (output: %s)", err, strings.TrimSpace(string(output)))
 	}
 
 	return strings.TrimSpace(string(output)) == "1", nil
@@ -405,10 +407,13 @@ func (s *Safety) listPostgresUserDatabases(ctx context.Context) ([]string, error
 		"-c", query,
 	}
 
-	// Only add -h flag if host is not localhost (to use Unix socket for peer auth)
-	if s.cfg.Host != "localhost" && s.cfg.Host != "127.0.0.1" && s.cfg.Host != "" {
-		args = append([]string{"-h", s.cfg.Host}, args...)
+	// Always add -h flag for explicit host connection (required for password auth)
+	// Empty or unset host defaults to localhost
+	host := s.cfg.Host
+	if host == "" {
+		host = "localhost"
 	}
+	args = append([]string{"-h", host}, args...)
 
 	cmd := exec.CommandContext(ctx, "psql", args...)
 
@@ -417,9 +422,10 @@ func (s *Safety) listPostgresUserDatabases(ctx context.Context) ([]string, error
 		cmd.Env = append(os.Environ(), fmt.Sprintf("PGPASSWORD=%s", s.cfg.Password))
 	}
 
-	output, err := cmd.Output()
+	output, err := cmd.CombinedOutput()
 	if err != nil {
-		return nil, fmt.Errorf("failed to list databases: %w", err)
+		// Include psql output in error for debugging
+		return nil, fmt.Errorf("failed to list databases: %w (output: %s)", err, strings.TrimSpace(string(output)))
 	}
 
 	// Parse output

internal/tui/backup_exec.go

@@ -454,65 +454,61 @@ func (m BackupExecutionModel) View() string {
 	} else {
 		// Show completion summary with detailed stats
 		if m.err != nil {
+			s.WriteString(errorStyle.Render("╔══════════════════════════════════════════════════════════════╗"))
 			s.WriteString("\n")
-			s.WriteString(errorStyle.Render("  ╔══════════════════════════════════════════════════════════╗"))
+			s.WriteString(errorStyle.Render("║              [FAIL] BACKUP FAILED                            ║"))
 			s.WriteString("\n")
-			s.WriteString(errorStyle.Render("  ║              [FAIL] BACKUP FAILED                        ║"))
-			s.WriteString("\n")
-			s.WriteString(errorStyle.Render("  ╚══════════════════════════════════════════════════════════╝"))
+			s.WriteString(errorStyle.Render("╚══════════════════════════════════════════════════════════════╝"))
 			s.WriteString("\n\n")
-			s.WriteString(errorStyle.Render(fmt.Sprintf("    Error: %v", m.err)))
+			s.WriteString(errorStyle.Render(fmt.Sprintf("  Error: %v", m.err)))
 			s.WriteString("\n")
 		} else {
+			s.WriteString(successStyle.Render("╔══════════════════════════════════════════════════════════════╗"))
 			s.WriteString("\n")
-			s.WriteString(successStyle.Render("  ╔══════════════════════════════════════════════════════════╗"))
+			s.WriteString(successStyle.Render("║           [OK] BACKUP COMPLETED SUCCESSFULLY                 ║"))
 			s.WriteString("\n")
-			s.WriteString(successStyle.Render("  ║           [OK] BACKUP COMPLETED SUCCESSFULLY             ║"))
-			s.WriteString("\n")
-			s.WriteString(successStyle.Render("  ╚══════════════════════════════════════════════════════════╝"))
+			s.WriteString(successStyle.Render("╚══════════════════════════════════════════════════════════════╝"))
 			s.WriteString("\n\n")
 
 			// Summary section
-			s.WriteString(infoStyle.Render("    ─── Summary ─────────────────────────────────────────────"))
+			s.WriteString(infoStyle.Render("  ─── Summary ───────────────────────────────────────────────"))
 			s.WriteString("\n\n")
 
 			// Backup type specific info
 			switch m.backupType {
 			case "cluster":
-				s.WriteString("      Type:          Cluster Backup\n")
+				s.WriteString("    Type:          Cluster Backup\n")
 				if m.dbTotal > 0 {
-					s.WriteString(fmt.Sprintf("      Databases:     %d backed up\n", m.dbTotal))
+					s.WriteString(fmt.Sprintf("    Databases:     %d backed up\n", m.dbTotal))
 				}
 			case "single":
-				s.WriteString("      Type:          Single Database Backup\n")
-				s.WriteString(fmt.Sprintf("      Database:      %s\n", m.databaseName))
+				s.WriteString("    Type:          Single Database Backup\n")
+				s.WriteString(fmt.Sprintf("    Database:      %s\n", m.databaseName))
 			case "sample":
-				s.WriteString("      Type:          Sample Backup\n")
-				s.WriteString(fmt.Sprintf("      Database:      %s\n", m.databaseName))
-				s.WriteString(fmt.Sprintf("      Sample Ratio:  %d\n", m.ratio))
+				s.WriteString("    Type:          Sample Backup\n")
+				s.WriteString(fmt.Sprintf("    Database:      %s\n", m.databaseName))
+				s.WriteString(fmt.Sprintf("    Sample Ratio:  %d\n", m.ratio))
 			}
 
 			s.WriteString("\n")
-
-			// Timing section
-			s.WriteString(infoStyle.Render("    ─── Timing ──────────────────────────────────────────────"))
-			s.WriteString("\n\n")
-
-			elapsed := time.Since(m.startTime)
-			s.WriteString(fmt.Sprintf("      Total Time:    %s\n", formatBackupDuration(elapsed)))
-
-			if m.backupType == "cluster" && m.dbTotal > 0 {
-				avgPerDB := elapsed / time.Duration(m.dbTotal)
-				s.WriteString(fmt.Sprintf("      Avg per DB:    %s\n", formatBackupDuration(avgPerDB)))
-			}
-
-			s.WriteString("\n")
-			s.WriteString(infoStyle.Render("    ─────────────────────────────────────────────────────────"))
-			s.WriteString("\n")
+		}
+
+		// Timing section (always shown, consistent with restore)
+		s.WriteString(infoStyle.Render("  ─── Timing ────────────────────────────────────────────────"))
+		s.WriteString("\n\n")
+
+		elapsed := time.Since(m.startTime)
+		s.WriteString(fmt.Sprintf("    Total Time:    %s\n", formatBackupDuration(elapsed)))
+
+		if m.backupType == "cluster" && m.dbTotal > 0 && m.err == nil {
+			avgPerDB := elapsed / time.Duration(m.dbTotal)
+			s.WriteString(fmt.Sprintf("    Avg per DB:    %s\n", formatBackupDuration(avgPerDB)))
 		}
 
 		s.WriteString("\n")
-		s.WriteString("  [KEY]  Press Enter or ESC to return to menu\n")
+		s.WriteString(infoStyle.Render("  ───────────────────────────────────────────────────────────"))
+		s.WriteString("\n\n")
+		s.WriteString(infoStyle.Render("  [KEYS]  Press Enter to continue"))
 	}
 
 	return s.String()

internal/tui/menu.go

@@ -299,9 +299,13 @@ func (m *MenuModel) View() string {
 
 	var s string
 
+	// Product branding header
+	brandLine := fmt.Sprintf("dbbackup v%s • Enterprise Database Backup & Recovery", m.config.Version)
+	s += "\n" + infoStyle.Render(brandLine) + "\n"
+
 	// Header
-	header := titleStyle.Render("Database Backup Tool - Interactive Menu")
-	s += fmt.Sprintf("\n%s\n\n", header)
+	header := titleStyle.Render("Interactive Menu")
+	s += fmt.Sprintf("%s\n\n", header)
 
 	if len(m.dbTypes) > 0 {
 		options := make([]string, len(m.dbTypes))

internal/tui/restore_preview.go

@@ -55,6 +55,7 @@ type RestorePreviewModel struct {
 	cleanClusterFirst bool     // For cluster restore: drop all user databases first
 	existingDBCount   int      // Number of existing user databases
 	existingDBs       []string // List of existing user databases
+	existingDBError   string   // Error message if database listing failed
 	safetyChecks      []SafetyCheck
 	checking          bool
 	canProceed        bool
@@ -102,6 +103,7 @@ type safetyCheckCompleteMsg struct {
 	canProceed      bool
 	existingDBCount int
 	existingDBs     []string
+	existingDBError string
 }
 
 func runSafetyChecks(cfg *config.Config, log logger.Logger, archive ArchiveInfo, targetDB string) tea.Cmd {
@@ -221,10 +223,12 @@ func runSafetyChecks(cfg *config.Config, log logger.Logger, archive ArchiveInfo,
 			check = SafetyCheck{Name: "Existing databases", Status: "checking", Critical: false}
 
 			// Get list of existing user databases (exclude templates and system DBs)
+			var existingDBError string
 			dbList, err := safety.ListUserDatabases(ctx)
 			if err != nil {
 				check.Status = "warning"
 				check.Message = fmt.Sprintf("Cannot list databases: %v", err)
+				existingDBError = err.Error()
 			} else {
 				existingDBCount = len(dbList)
 				existingDBs = dbList
@@ -238,6 +242,14 @@ func runSafetyChecks(cfg *config.Config, log logger.Logger, archive ArchiveInfo,
 				}
 			}
 			checks = append(checks, check)
+
+			return safetyCheckCompleteMsg{
+				checks:          checks,
+				canProceed:      canProceed,
+				existingDBCount: existingDBCount,
+				existingDBs:     existingDBs,
+				existingDBError: existingDBError,
+			}
 		}
 
 		return safetyCheckCompleteMsg{
@@ -257,6 +269,7 @@ func (m RestorePreviewModel) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 		m.canProceed = msg.canProceed
 		m.existingDBCount = msg.existingDBCount
 		m.existingDBs = msg.existingDBs
+		m.existingDBError = msg.existingDBError
 		// Auto-forward in auto-confirm mode
 		if m.config.TUIAutoConfirm {
 			return m.parent, tea.Quit
@@ -275,12 +288,17 @@ func (m RestorePreviewModel) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 
 		case "c":
 			if m.mode == "restore-cluster" {
-				// Toggle cluster cleanup
-				m.cleanClusterFirst = !m.cleanClusterFirst
-				if m.cleanClusterFirst {
-					m.message = checkWarningStyle.Render(fmt.Sprintf("[WARN] Will drop %d existing database(s) before restore", m.existingDBCount))
+				// Prevent toggle if we couldn't detect existing databases
+				if m.existingDBError != "" {
+					m.message = checkWarningStyle.Render("[WARN] Cannot enable cleanup - database detection failed")
 				} else {
-					m.message = fmt.Sprintf("Clean cluster first: disabled")
+					// Toggle cluster cleanup
+					m.cleanClusterFirst = !m.cleanClusterFirst
+					if m.cleanClusterFirst {
+						m.message = checkWarningStyle.Render(fmt.Sprintf("[WARN] Will drop %d existing database(s) before restore", m.existingDBCount))
+					} else {
+						m.message = fmt.Sprintf("Clean cluster first: disabled")
+					}
 				}
 			} else {
 				// Toggle create if missing
@@ -382,7 +400,11 @@ func (m RestorePreviewModel) View() string {
 		s.WriteString("\n")
 		s.WriteString(fmt.Sprintf("  Host: %s:%d\n", m.config.Host, m.config.Port))
 
-		if m.existingDBCount > 0 {
+		if m.existingDBError != "" {
+			// Show error when database listing failed
+			s.WriteString(checkWarningStyle.Render(fmt.Sprintf("  Existing Databases: Unable to detect (%s)\n", m.existingDBError)))
+			s.WriteString(infoStyle.Render("  (Cleanup option disabled - cannot verify database status)\n"))
+		} else if m.existingDBCount > 0 {
 			s.WriteString(fmt.Sprintf("  Existing Databases: %d found\n", m.existingDBCount))
 
 			// Show first few database names