refactor(profiles): replace large-db profile with composable LargeDBMode

BREAKING CHANGE: Removed 'large-db' as standalone profile

New Design:
- Resource Profiles now purely represent VM capacity:
  conservative, balanced, performance, max-performance
- LargeDBMode is a separate boolean toggle that modifies any profile:
  - Reduces ClusterParallelism and Jobs by 50%
  - Forces MaxLocksPerTxn = 8192
  - Increases MaintenanceWorkMem

TUI Changes:
- 'l' key now toggles LargeDBMode ON/OFF instead of applying large-db profile
- New 'Large DB Mode' setting in settings menu
- Settings are persisted to .dbbackup.conf

This allows any resource profile to be combined with large database
optimization, giving users more flexibility on both small and large VMs.

README.md

@@ -221,7 +221,7 @@ Configuration Settings
   Database User: postgres
   SSL Mode: prefer
 
-[KEYS]  ↑↓ navigate | Enter edit | 'l' large-db | 'c' conservative | 'p' recommend | 's' save | 'q' menu
+[KEYS]  ↑↓ navigate | Enter edit | 'l' toggle LargeDB | 'c' conservative | 'p' recommend | 's' save | 'q' menu
 ```
 
 **Resource Profiles for Large Databases:**
@@ -233,9 +233,11 @@ When restoring large databases on VMs with limited resources, use the resource p
 | conservative | 1 | 1 | Small VMs (<16GB RAM) |
 | balanced | 2 | 2-4 | Medium VMs (16-32GB RAM) |
 | performance | 4 | 4-8 | Large servers (32GB+ RAM) |
-| large-db | 1 | 2 | Large databases on any hardware |
+| max-performance | 8 | 8-16 | High-end servers (64GB+) |
 
-**Quick shortcuts:** Press `l` to apply large-db profile, `c` for conservative, `p` to show recommendation.
+**Large DB Mode:** Toggle with `l` key. Reduces parallelism by 50% and sets max_locks_per_transaction=8192 for complex databases with many tables/LOBs.
+
+**Quick shortcuts:** Press `l` to toggle Large DB Mode, `c` for conservative, `p` to show recommendation.
 
 **Database Status:**
 ```

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**: 2026-01-18_11:06:11_UTC
+- **Build Time**: 2026-01-18_11:19:47_UTC
-- **Git Commit**: ea4337e
+- **Git Commit**: 490a12f
 
 ## Recent Updates (v1.1.0)
 - ✅ Fixed TUI progress display with line-by-line output

internal/config/config.go

@@ -37,7 +37,8 @@ type Config struct {
 	CPUWorkloadType  string // "cpu-intensive", "io-intensive", "balanced"
 
 	// Resource profile for backup/restore operations
-	ResourceProfile string // "conservative", "balanced", "performance", "max-performance", "large-db"
+	ResourceProfile string // "conservative", "balanced", "performance", "max-performance"
+	LargeDBMode     bool   // Enable large database mode (reduces parallelism, increases max_locks)
 
 	// CPU detection
 	CPUDetector *cpu.Detector
@@ -209,6 +210,7 @@ func New() *Config {
 		AutoDetectCores:  getEnvBool("AUTO_DETECT_CORES", true),
 		CPUWorkloadType:  getEnvString("CPU_WORKLOAD_TYPE", "balanced"),
 		ResourceProfile:  defaultProfile,
+		LargeDBMode:      getEnvBool("LARGE_DB_MODE", false),
 
 		// CPU and memory detection
 		CPUDetector: cpuDetector,
@@ -430,7 +432,7 @@ func (c *Config) ApplyResourceProfile(profileName string) error {
 		return &ConfigError{
 			Field:   "resource_profile",
 			Value:   profileName,
-			Message: "unknown profile. Valid profiles: conservative, balanced, performance, max-performance, large-db",
+			Message: "unknown profile. Valid profiles: conservative, balanced, performance, max-performance",
 		}
 	}
 
@@ -457,8 +459,19 @@ func (c *Config) GetResourceProfileRecommendation(isLargeDB bool) (string, strin
 }
 
 // GetCurrentProfile returns the current resource profile details
+// If LargeDBMode is enabled, returns a modified profile with reduced parallelism
 func (c *Config) GetCurrentProfile() *cpu.ResourceProfile {
-	return cpu.GetProfileByName(c.ResourceProfile)
+	profile := cpu.GetProfileByName(c.ResourceProfile)
+	if profile == nil {
+		return nil
+	}
+
+	// Apply LargeDBMode modifier if enabled
+	if c.LargeDBMode {
+		return cpu.ApplyLargeDBMode(profile)
+	}
+
+	return profile
 }
 
 // GetCPUInfo returns CPU information, detecting if necessary

internal/config/persist.go

@@ -31,6 +31,8 @@ type LocalConfig struct {
 	CPUWorkload     string
 	MaxCores        int
 	ClusterTimeout  int  // Cluster operation timeout in minutes (default: 1440 = 24 hours)
+	ResourceProfile string
+	LargeDBMode     bool // Enable large database mode (reduces parallelism, increases locks)
 
 	// Security settings
 	RetentionDays int
@@ -126,6 +128,10 @@ func LoadLocalConfig() (*LocalConfig, error) {
 				if ct, err := strconv.Atoi(value); err == nil {
 					cfg.ClusterTimeout = ct
 				}
+			case "resource_profile":
+				cfg.ResourceProfile = value
+			case "large_db_mode":
+				cfg.LargeDBMode = value == "true" || value == "1"
 			}
 		case "security":
 			switch key {
@@ -207,6 +213,12 @@ func SaveLocalConfig(cfg *LocalConfig) error {
 	if cfg.ClusterTimeout != 0 {
 		sb.WriteString(fmt.Sprintf("cluster_timeout = %d\n", cfg.ClusterTimeout))
 	}
+	if cfg.ResourceProfile != "" {
+		sb.WriteString(fmt.Sprintf("resource_profile = %s\n", cfg.ResourceProfile))
+	}
+	if cfg.LargeDBMode {
+		sb.WriteString("large_db_mode = true\n")
+	}
 	sb.WriteString("\n")
 
 	// Security section
@@ -280,6 +292,14 @@ func ApplyLocalConfig(cfg *Config, local *LocalConfig) {
 	if local.ClusterTimeout != 0 {
 		cfg.ClusterTimeoutMinutes = local.ClusterTimeout
 	}
+	// Apply resource profile settings
+	if local.ResourceProfile != "" {
+		cfg.ResourceProfile = local.ResourceProfile
+	}
+	// LargeDBMode is a boolean - apply if true in config
+	if local.LargeDBMode {
+		cfg.LargeDBMode = true
+	}
 	if cfg.RetentionDays == 30 && local.RetentionDays != 0 {
 		cfg.RetentionDays = local.RetentionDays
 	}
@@ -308,6 +328,8 @@ func ConfigFromConfig(cfg *Config) *LocalConfig {
 		CPUWorkload:     cfg.CPUWorkloadType,
 		MaxCores:        cfg.MaxCores,
 		ClusterTimeout:  cfg.ClusterTimeoutMinutes,
+		ResourceProfile: cfg.ResourceProfile,
+		LargeDBMode:     cfg.LargeDBMode,
 		RetentionDays:   cfg.RetentionDays,
 		MinBackups:      cfg.MinBackups,
 		MaxRetries:      cfg.MaxRetries,

internal/cpu/profiles.go

@@ -90,32 +90,17 @@ var (
 		DumpJobs:            16,
 		MaintenanceWorkMem:  "2GB",
 		MaxLocksPerTxn:      512,
-		RecommendedForLarge: false, // Large DBs should use conservative
+		RecommendedForLarge: false, // Large DBs should use LargeDBMode
 		MinMemoryGB:         64,
 		MinCores:            16,
 	}
 
-	// ProfileLargeDB - Optimized specifically for large databases
+	// AllProfiles contains all available profiles (VM resource-based)
-	ProfileLargeDB = ResourceProfile{
-		Name:                "large-db",
-		Description:         "Optimized for large databases with many tables/BLOBs. Prevents 'out of shared memory' errors.",
-		ClusterParallelism:  1,
-		Jobs:                2,
-		DumpJobs:            2,
-		MaintenanceWorkMem:  "1GB",
-		MaxLocksPerTxn:      8192,
-		RecommendedForLarge: true,
-		MinMemoryGB:         8,
-		MinCores:            2,
-	}
-
-	// AllProfiles contains all available profiles
 	AllProfiles = []ResourceProfile{
 		ProfileConservative,
 		ProfileBalanced,
 		ProfilePerformance,
 		ProfileMaxPerformance,
-		ProfileLargeDB,
 	}
 )
 
@@ -129,6 +114,51 @@ func GetProfileByName(name string) *ResourceProfile {
 	return nil
 }
 
+// ApplyLargeDBMode modifies a profile for large database operations.
+// This is a modifier that reduces parallelism and increases max_locks_per_transaction
+// to prevent "out of shared memory" errors with large databases (many tables, LOBs, etc.).
+// It returns a new profile with adjusted settings, leaving the original unchanged.
+func ApplyLargeDBMode(profile *ResourceProfile) *ResourceProfile {
+	if profile == nil {
+		return nil
+	}
+
+	// Create a copy with adjusted settings
+	modified := *profile
+
+	// Add "(large-db)" suffix to indicate this is modified
+	modified.Name = profile.Name + " +large-db"
+	modified.Description = fmt.Sprintf("%s [LargeDBMode: reduced parallelism, high locks]", profile.Description)
+
+	// Reduce parallelism to avoid lock exhaustion
+	// Rule: halve parallelism, minimum 1
+	modified.ClusterParallelism = max(1, profile.ClusterParallelism/2)
+	modified.Jobs = max(1, profile.Jobs/2)
+	modified.DumpJobs = max(2, profile.DumpJobs/2)
+
+	// Force high max_locks_per_transaction for large schemas
+	modified.MaxLocksPerTxn = 8192
+
+	// Increase maintenance_work_mem for complex operations
+	// Keep or boost maintenance work mem
+	modified.MaintenanceWorkMem = "1GB"
+	if profile.MinMemoryGB >= 32 {
+		modified.MaintenanceWorkMem = "2GB"
+	}
+
+	modified.RecommendedForLarge = true
+
+	return &modified
+}
+
+// max returns the larger of two integers
+func max(a, b int) int {
+	if a > b {
+		return a
+	}
+	return b
+}
+
 // DetectMemory detects system memory information
 func DetectMemory() (*MemoryInfo, error) {
 	info := &MemoryInfo{
@@ -293,11 +323,11 @@ func RecommendProfile(cpuInfo *CPUInfo, memInfo *MemoryInfo, isLargeDB bool) *Re
 		memGB = memInfo.TotalGB
 	}
 
-	// Special case: large databases should always use conservative/large-db profile
+	// Special case: large databases should use conservative profile
+	// The caller should also enable LargeDBMode for increased MaxLocksPerTxn
 	if isLargeDB {
-		if memGB >= 32 && cores >= 8 {
+		// For large DBs, recommend conservative regardless of resources
-			return &ProfileLargeDB // Still conservative but with more memory for maintenance
+		// LargeDBMode flag will handle the lock settings separately
-		}
 		return &ProfileConservative
 	}
 
@@ -339,7 +369,7 @@ func RecommendProfileWithReason(cpuInfo *CPUInfo, memInfo *MemoryInfo, isLargeDB
 	profile := RecommendProfile(cpuInfo, memInfo, isLargeDB)
 
 	if isLargeDB {
-		reason.WriteString("Large database detected - using conservative settings to avoid 'out of shared memory' errors.")
+		reason.WriteString("Large database mode - using conservative settings. Enable LargeDBMode for higher max_locks.")
 	} else if profile.Name == "conservative" {
 		reason.WriteString("Limited resources detected - using conservative profile for stability.")
 	} else if profile.Name == "max-performance" {

internal/tui/restore_exec.go

@@ -1159,8 +1159,8 @@ func formatRestoreError(errStr string) string {
 		s.WriteString("    If you reduced VM size or max_connections, you need higher\n")
 		s.WriteString("    max_locks_per_transaction to compensate.\n\n")
 		s.WriteString(successStyle.Render("    FIX OPTIONS:\n"))
-		s.WriteString("    1. Use 'conservative' or 'large-db' profile in Settings\n")
+		s.WriteString("    1. Enable 'Large DB Mode' in Settings\n")
-		s.WriteString("       (press 'l' for large-db, 'c' for conservative)\n\n")
+		s.WriteString("       (press 'l' to toggle, reduces parallelism, increases locks)\n\n")
 		s.WriteString("    2. Increase PostgreSQL locks:\n")
 		s.WriteString("       ALTER SYSTEM SET max_locks_per_transaction = 4096;\n")
 		s.WriteString("       Then RESTART PostgreSQL.\n\n")
@@ -1186,7 +1186,7 @@ func formatRestoreError(errStr string) string {
 		s.WriteString("\n\n")
 		s.WriteString("    1. Check the full error log for details\n")
 		s.WriteString("    2. Try restoring with 'conservative' profile (press 'c')\n")
-		s.WriteString("    3. For large databases, use 'large-db' profile (press 'l')\n")
+		s.WriteString("    3. For complex databases, enable 'Large DB Mode' (press 'l')\n")
 	}
 
 	s.WriteString("\n")

internal/tui/restore_preview.go

@@ -410,6 +410,10 @@ func (m RestorePreviewModel) View() string {
 		} else {
 			s.WriteString(fmt.Sprintf("  Resource Profile: %s\n", m.config.ResourceProfile))
 		}
+		// Show Large DB Mode status
+		if m.config.LargeDBMode {
+			s.WriteString("  Large DB Mode: ON (reduced parallelism, high locks)\n")
+		}
 		s.WriteString(fmt.Sprintf("  CPU Workload: %s\n", m.config.CPUWorkloadType))
 		s.WriteString(fmt.Sprintf("  Cluster Parallelism: %d databases\n", m.config.ClusterParallelism))
 

internal/tui/settings.go

@@ -113,7 +113,7 @@ func NewSettingsModel(cfg *config.Config, log logger.Logger, parent tea.Model) S
 				return c.ResourceProfile
 			},
 			Update: func(c *config.Config, v string) error {
-				profiles := []string{"conservative", "balanced", "performance", "max-performance", "large-db"}
+				profiles := []string{"conservative", "balanced", "performance", "max-performance"}
 				currentIdx := 0
 				for i, p := range profiles {
 					if c.ResourceProfile == p {
@@ -125,7 +125,23 @@ func NewSettingsModel(cfg *config.Config, log logger.Logger, parent tea.Model) S
 				return c.ApplyResourceProfile(profiles[nextIdx])
 			},
 			Type:        "selector",
-			Description: "Resource profile for backup/restore. Use 'conservative' or 'large-db' for large databases on small VMs.",
+			Description: "Resource profile for VM capacity. Toggle 'l' for Large DB Mode on any profile.",
+		},
+		{
+			Key:         "large_db_mode",
+			DisplayName: "Large DB Mode",
+			Value: func(c *config.Config) string {
+				if c.LargeDBMode {
+					return "ON (↓parallelism, ↑locks)"
+				}
+				return "OFF"
+			},
+			Update: func(c *config.Config, v string) error {
+				c.LargeDBMode = !c.LargeDBMode
+				return nil
+			},
+			Type:        "selector",
+			Description: "Enable for databases with many tables/LOBs. Reduces parallelism, increases max_locks_per_transaction.",
 		},
 		{
 			Key:         "cluster_parallelism",
@@ -574,8 +590,8 @@ func (m SettingsModel) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 			return m.saveSettings()
 
 		case "l":
-			// Quick shortcut: Apply "large-db" profile for large databases
+			// Quick shortcut: Toggle Large DB Mode
-			return m.applyLargeDBProfile()
+			return m.toggleLargeDBMode()
 
 		case "c":
 			// Quick shortcut: Apply "conservative" profile for constrained VMs
@@ -590,13 +606,20 @@ func (m SettingsModel) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 	return m, nil
 }
 
-// applyLargeDBProfile applies the large-db profile optimized for large databases
+// toggleLargeDBMode toggles the Large DB Mode flag
-func (m SettingsModel) applyLargeDBProfile() (tea.Model, tea.Cmd) {
+func (m SettingsModel) toggleLargeDBMode() (tea.Model, tea.Cmd) {
-	if err := m.config.ApplyResourceProfile("large-db"); err != nil {
+	m.config.LargeDBMode = !m.config.LargeDBMode
-		m.message = errorStyle.Render(fmt.Sprintf("[FAIL] %s", err.Error()))
+	if m.config.LargeDBMode {
-		return m, nil
+		profile := m.config.GetCurrentProfile()
+		m.message = successStyle.Render(fmt.Sprintf(
+			"[ON] Large DB Mode enabled: %s → Parallel=%d, Jobs=%d, MaxLocks=%d",
+			profile.Name, profile.ClusterParallelism, profile.Jobs, profile.MaxLocksPerTxn))
+	} else {
+		profile := m.config.GetCurrentProfile()
+		m.message = successStyle.Render(fmt.Sprintf(
+			"[OFF] Large DB Mode disabled: %s → Parallel=%d, Jobs=%d",
+			profile.Name, profile.ClusterParallelism, profile.Jobs))
 	}
-	m.message = successStyle.Render("[OK] Applied 'large-db' profile: Cluster=1, Jobs=2. Optimized for large DBs to avoid 'out of shared memory' errors.")
 	return m, nil
 }
 
@@ -613,14 +636,19 @@ func (m SettingsModel) applyConservativeProfile() (tea.Model, tea.Cmd) {
 // showProfileRecommendation displays the recommended profile based on system resources
 func (m SettingsModel) showProfileRecommendation() (tea.Model, tea.Cmd) {
 	profileName, reason := m.config.GetResourceProfileRecommendation(false)
-	largeDBProfile, largeDBReason := m.config.GetResourceProfileRecommendation(true)
+
+	var largeDBHint string
+	if m.config.LargeDBMode {
+		largeDBHint = "Large DB Mode: ON"
+	} else {
+		largeDBHint = "Large DB Mode: OFF (press 'l' to enable)"
+	}
 
 	m.message = infoStyle.Render(fmt.Sprintf(
-		"[RECOMMEND] Default: %s | For Large DBs: %s\n"+
+		"[RECOMMEND] Profile: %s | %s\n"+
 			"  → %s\n"+
-			"  → Large DB: %s\n"+
+			"  Press 'l' to toggle Large DB Mode, 'c' for conservative",
-			"  Press 'l' for large-db profile, 'c' for conservative",
+		profileName, largeDBHint, reason))
-		profileName, largeDBProfile, reason, largeDBReason))
 	return m, nil
 }
 
@@ -907,9 +935,9 @@ func (m SettingsModel) View() string {
 		} else {
 			// Show different help based on current selection
 			if m.cursor >= 0 && m.cursor < len(m.settings) && m.settings[m.cursor].Type == "path" {
-				footer = infoStyle.Render("\n[KEYS]  ↑↓ navigate | Enter edit | Tab dirs | 'l' large-db | 'c' conservative | 'p' recommend | 's' save | 'q' menu")
+				footer = infoStyle.Render("\n[KEYS]  ↑↓ navigate | Enter edit | Tab dirs | 'l' toggle LargeDB | 'c' conservative | 'p' recommend | 's' save | 'q' menu")
 			} else {
-				footer = infoStyle.Render("\n[KEYS]  ↑↓ navigate | Enter edit | 'l' large-db profile | 'c' conservative | 'p' recommend | 's' save | 'r' reset | 'q' menu")
+				footer = infoStyle.Render("\n[KEYS]  ↑↓ navigate | Enter edit | 'l' toggle LargeDB mode | 'c' conservative | 'p' recommend | 's' save | 'r' reset | 'q' menu")
 			}
 		}
 	}