feat: comprehensive preflight checks for cluster restore

- Linux system checks (read-only from /proc, no auth needed):
  * shmmax, shmall kernel limits
  * Available RAM check

- PostgreSQL auto-tuning:
  * max_locks_per_transaction scaled by BLOB count
  * maintenance_work_mem boosted to 2GB for faster indexes
  * All settings auto-reset after restore (even on failure)

- Archive analysis:
  * Count BLOBs per database (pg_restore -l or zgrep)
  * Scale lock boost: 2048 (default) → 4096/8192/16384 based on count

- Nice TUI preflight summary display with ✓/⚠ indicators

bin/README.md

@@ -4,8 +4,8 @@ This directory contains pre-compiled binaries for the DB Backup Tool across mult
 
 ## Build Information
 - **Version**: 3.42.10
-- **Build Time**: 2026-01-13_13:40:58_UTC
+- **Build Time**: 2026-01-14_14:06:01_UTC
-- **Git Commit**: 222bdbe
+- **Git Commit**: 22a7b9e
 
 ## Recent Updates (v1.1.0)
 - ✅ Fixed TUI progress display with line-by-line output

internal/restore/engine.go

@@ -2,10 +2,12 @@ package restore
 
 import (
 	"context"
+	"database/sql"
 	"fmt"
 	"os"
 	"os/exec"
 	"path/filepath"
+	"strconv"
 	"strings"
 	"sync"
 	"sync/atomic"
@@ -17,6 +19,8 @@ import (
 	"dbbackup/internal/logger"
 	"dbbackup/internal/progress"
 	"dbbackup/internal/security"
+
+	_ "github.com/jackc/pgx/v5/stdlib" // PostgreSQL driver
 )
 
 // Engine handles database restore operations
@@ -925,6 +929,38 @@ func (e *Engine) RestoreCluster(ctx context.Context, archivePath string) error {
 	}
 	e.log.Info("All dump files passed validation")
 
+	// Run comprehensive preflight checks (Linux system + PostgreSQL + Archive analysis)
+	preflight, preflightErr := e.RunPreflightChecks(ctx, dumpsDir, entries)
+	if preflightErr != nil {
+		e.log.Warn("Preflight checks failed", "error", preflightErr)
+	}
+
+	// Calculate optimal lock boost based on BLOB count
+	lockBoostValue := 2048 // Default
+	if preflight != nil && preflight.Archive.RecommendedLockBoost > 0 {
+		lockBoostValue = preflight.Archive.RecommendedLockBoost
+	}
+
+	// AUTO-TUNE: Boost PostgreSQL settings for large restores
+	e.progress.Update("Tuning PostgreSQL for large restore...")
+	originalSettings, tuneErr := e.boostPostgreSQLSettings(ctx, lockBoostValue)
+	if tuneErr != nil {
+		e.log.Warn("Could not boost PostgreSQL settings - restore may fail on BLOB-heavy databases",
+			"error", tuneErr)
+	} else {
+		e.log.Info("Boosted PostgreSQL settings for restore",
+			"max_locks_per_transaction", fmt.Sprintf("%d → %d", originalSettings.MaxLocks, lockBoostValue),
+			"maintenance_work_mem", fmt.Sprintf("%s → 2GB", originalSettings.MaintenanceWorkMem))
+		// Ensure we reset settings when done (even on failure)
+		defer func() {
+			if resetErr := e.resetPostgreSQLSettings(ctx, originalSettings); resetErr != nil {
+				e.log.Warn("Could not reset PostgreSQL settings", "error", resetErr)
+			} else {
+				e.log.Info("Reset PostgreSQL settings to original values")
+			}
+		}()
+	}
+
 	var failedDBs []string
 	totalDBs := 0
 
@@ -1617,3 +1653,173 @@ func (e *Engine) quickValidateSQLDump(archivePath string, compressed bool) error
 	e.log.Debug("SQL dump validation passed", "path", archivePath)
 	return nil
 }
+
+// boostLockCapacity temporarily increases max_locks_per_transaction to prevent OOM
+// during large restores with many BLOBs. Returns the original value for later reset.
+// Uses ALTER SYSTEM + pg_reload_conf() so no restart is needed.
+func (e *Engine) boostLockCapacity(ctx context.Context) (int, error) {
+	// Connect to PostgreSQL to run system commands
+	connStr := fmt.Sprintf("host=%s port=%d user=%s password=%s dbname=postgres sslmode=disable",
+		e.cfg.Host, e.cfg.Port, e.cfg.User, e.cfg.Password)
+
+	// For localhost, use Unix socket
+	if e.cfg.Host == "localhost" || e.cfg.Host == "" {
+		connStr = fmt.Sprintf("user=%s password=%s dbname=postgres sslmode=disable",
+			e.cfg.User, e.cfg.Password)
+	}
+
+	db, err := sql.Open("pgx", connStr)
+	if err != nil {
+		return 0, fmt.Errorf("failed to connect: %w", err)
+	}
+	defer db.Close()
+
+	// Get current value
+	var currentValue int
+	err = db.QueryRowContext(ctx, "SHOW max_locks_per_transaction").Scan(&currentValue)
+	if err != nil {
+		// Try parsing as string (some versions return string)
+		var currentValueStr string
+		err = db.QueryRowContext(ctx, "SHOW max_locks_per_transaction").Scan(&currentValueStr)
+		if err != nil {
+			return 0, fmt.Errorf("failed to get current max_locks_per_transaction: %w", err)
+		}
+		fmt.Sscanf(currentValueStr, "%d", &currentValue)
+	}
+
+	// Skip if already high enough
+	if currentValue >= 2048 {
+		e.log.Info("max_locks_per_transaction already sufficient", "value", currentValue)
+		return currentValue, nil
+	}
+
+	// Boost to 2048 (enough for most BLOB-heavy databases)
+	_, err = db.ExecContext(ctx, "ALTER SYSTEM SET max_locks_per_transaction = 2048")
+	if err != nil {
+		return currentValue, fmt.Errorf("failed to set max_locks_per_transaction: %w", err)
+	}
+
+	// Reload config without restart
+	_, err = db.ExecContext(ctx, "SELECT pg_reload_conf()")
+	if err != nil {
+		return currentValue, fmt.Errorf("failed to reload config: %w", err)
+	}
+
+	return currentValue, nil
+}
+
+// resetLockCapacity restores the original max_locks_per_transaction value
+func (e *Engine) resetLockCapacity(ctx context.Context, originalValue int) error {
+	connStr := fmt.Sprintf("host=%s port=%d user=%s password=%s dbname=postgres sslmode=disable",
+		e.cfg.Host, e.cfg.Port, e.cfg.User, e.cfg.Password)
+
+	if e.cfg.Host == "localhost" || e.cfg.Host == "" {
+		connStr = fmt.Sprintf("user=%s password=%s dbname=postgres sslmode=disable",
+			e.cfg.User, e.cfg.Password)
+	}
+
+	db, err := sql.Open("pgx", connStr)
+	if err != nil {
+		return fmt.Errorf("failed to connect: %w", err)
+	}
+	defer db.Close()
+
+	// Reset to original value (or use RESET to go back to default)
+	if originalValue == 64 { // Default value
+		_, err = db.ExecContext(ctx, "ALTER SYSTEM RESET max_locks_per_transaction")
+	} else {
+		_, err = db.ExecContext(ctx, fmt.Sprintf("ALTER SYSTEM SET max_locks_per_transaction = %d", originalValue))
+	}
+	if err != nil {
+		return fmt.Errorf("failed to reset max_locks_per_transaction: %w", err)
+	}
+
+	// Reload config
+	_, err = db.ExecContext(ctx, "SELECT pg_reload_conf()")
+	if err != nil {
+		return fmt.Errorf("failed to reload config: %w", err)
+	}
+
+	return nil
+}
+
+// OriginalSettings stores PostgreSQL settings to restore after operation
+type OriginalSettings struct {
+	MaxLocks           int
+	MaintenanceWorkMem string
+}
+
+// boostPostgreSQLSettings boosts multiple PostgreSQL settings for large restores
+func (e *Engine) boostPostgreSQLSettings(ctx context.Context, lockBoostValue int) (*OriginalSettings, error) {
+	connStr := e.buildConnString()
+	db, err := sql.Open("pgx", connStr)
+	if err != nil {
+		return nil, fmt.Errorf("failed to connect: %w", err)
+	}
+	defer db.Close()
+
+	original := &OriginalSettings{}
+
+	// Get current max_locks_per_transaction
+	var maxLocksStr string
+	if err := db.QueryRowContext(ctx, "SHOW max_locks_per_transaction").Scan(&maxLocksStr); err == nil {
+		original.MaxLocks, _ = strconv.Atoi(maxLocksStr)
+	}
+
+	// Get current maintenance_work_mem
+	db.QueryRowContext(ctx, "SHOW maintenance_work_mem").Scan(&original.MaintenanceWorkMem)
+
+	// Boost max_locks_per_transaction (if not already high enough)
+	if original.MaxLocks < lockBoostValue {
+		_, err = db.ExecContext(ctx, fmt.Sprintf("ALTER SYSTEM SET max_locks_per_transaction = %d", lockBoostValue))
+		if err != nil {
+			e.log.Warn("Could not boost max_locks_per_transaction", "error", err)
+		}
+	}
+
+	// Boost maintenance_work_mem to 2GB for faster index creation
+	_, err = db.ExecContext(ctx, "ALTER SYSTEM SET maintenance_work_mem = '2GB'")
+	if err != nil {
+		e.log.Warn("Could not boost maintenance_work_mem", "error", err)
+	}
+
+	// Reload config to apply changes (no restart needed for these settings)
+	_, err = db.ExecContext(ctx, "SELECT pg_reload_conf()")
+	if err != nil {
+		return original, fmt.Errorf("failed to reload config: %w", err)
+	}
+
+	return original, nil
+}
+
+// resetPostgreSQLSettings restores original PostgreSQL settings
+func (e *Engine) resetPostgreSQLSettings(ctx context.Context, original *OriginalSettings) error {
+	connStr := e.buildConnString()
+	db, err := sql.Open("pgx", connStr)
+	if err != nil {
+		return fmt.Errorf("failed to connect: %w", err)
+	}
+	defer db.Close()
+
+	// Reset max_locks_per_transaction
+	if original.MaxLocks == 64 { // Default
+		db.ExecContext(ctx, "ALTER SYSTEM RESET max_locks_per_transaction")
+	} else if original.MaxLocks > 0 {
+		db.ExecContext(ctx, fmt.Sprintf("ALTER SYSTEM SET max_locks_per_transaction = %d", original.MaxLocks))
+	}
+
+	// Reset maintenance_work_mem
+	if original.MaintenanceWorkMem == "64MB" { // Default
+		db.ExecContext(ctx, "ALTER SYSTEM RESET maintenance_work_mem")
+	} else if original.MaintenanceWorkMem != "" {
+		db.ExecContext(ctx, fmt.Sprintf("ALTER SYSTEM SET maintenance_work_mem = '%s'", original.MaintenanceWorkMem))
+	}
+
+	// Reload config
+	_, err = db.ExecContext(ctx, "SELECT pg_reload_conf()")
+	if err != nil {
+		return fmt.Errorf("failed to reload config: %w", err)
+	}
+
+	return nil
+}

internal/restore/preflight.go

@@ -0,0 +1,435 @@
+package restore
+
+import (
+	"bufio"
+	"context"
+	"database/sql"
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"runtime"
+	"strconv"
+	"strings"
+	"time"
+)
+
+// PreflightResult contains all preflight check results
+type PreflightResult struct {
+	// Linux system checks
+	Linux LinuxChecks
+
+	// PostgreSQL checks
+	PostgreSQL PostgreSQLChecks
+
+	// Archive analysis
+	Archive ArchiveChecks
+
+	// Overall status
+	CanProceed bool
+	Warnings   []string
+	Errors     []string
+}
+
+// LinuxChecks contains Linux kernel/system checks
+type LinuxChecks struct {
+	ShmMax         int64  // /proc/sys/kernel/shmmax
+	ShmAll         int64  // /proc/sys/kernel/shmall
+	MemTotal       int64  // Total RAM in bytes
+	MemAvailable   int64  // Available RAM in bytes
+	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
+type PostgreSQLChecks struct {
+	MaxLocksPerTransaction int    // Current setting
+	MaintenanceWorkMem     string // Current setting
+	SharedBuffers          string // Current setting (info only)
+	MaxConnections         int    // Current setting
+	Version                string // PostgreSQL version
+	IsSuperuser            bool   // Can we modify settings?
+}
+
+// ArchiveChecks contains analysis of the backup archive
+type ArchiveChecks struct {
+	TotalDatabases int
+	TotalBlobCount int            // Estimated total BLOBs across all databases
+	BlobsByDB      map[string]int // BLOBs per database
+	HasLargeBlobs  bool           // Any DB with >1000 BLOBs?
+	RecommendedLockBoost int      // Calculated lock boost value
+}
+
+// RunPreflightChecks performs all preflight checks before a cluster restore
+func (e *Engine) RunPreflightChecks(ctx context.Context, dumpsDir string, entries []os.DirEntry) (*PreflightResult, error) {
+	result := &PreflightResult{
+		CanProceed: true,
+		Archive: ArchiveChecks{
+			BlobsByDB: make(map[string]int),
+		},
+	}
+
+	e.progress.Update("[PREFLIGHT] Running system checks...")
+	e.log.Info("Starting preflight checks for cluster restore")
+
+	// 1. Linux system checks (read-only from /proc)
+	e.checkLinuxSystem(result)
+
+	// 2. PostgreSQL checks (via existing connection)
+	e.checkPostgreSQL(ctx, result)
+
+	// 3. Archive analysis (count BLOBs to scale lock boost)
+	e.analyzeArchive(ctx, dumpsDir, entries, result)
+
+	// 4. Calculate recommended settings
+	e.calculateRecommendations(result)
+
+	// 5. Print summary
+	e.printPreflightSummary(result)
+
+	return result, nil
+}
+
+// checkLinuxSystem reads kernel limits from /proc (no auth needed)
+func (e *Engine) checkLinuxSystem(result *PreflightResult) {
+	result.Linux.IsLinux = runtime.GOOS == "linux"
+
+	if !result.Linux.IsLinux {
+		e.log.Info("Not running on Linux - skipping kernel checks", "os", runtime.GOOS)
+		return
+	}
+
+	// Read shmmax
+	if data, err := os.ReadFile("/proc/sys/kernel/shmmax"); err == nil {
+		val, _ := strconv.ParseInt(strings.TrimSpace(string(data)), 10, 64)
+		result.Linux.ShmMax = val
+		// 8GB minimum for large restores
+		result.Linux.ShmMaxOK = val >= 8*1024*1024*1024
+	}
+
+	// Read shmall (in pages, typically 4KB each)
+	if data, err := os.ReadFile("/proc/sys/kernel/shmall"); err == nil {
+		val, _ := strconv.ParseInt(strings.TrimSpace(string(data)), 10, 64)
+		result.Linux.ShmAll = val
+		// 2M pages = 8GB minimum
+		result.Linux.ShmAllOK = val >= 2*1024*1024
+	}
+
+	// Read memory info
+	if file, err := os.Open("/proc/meminfo"); err == nil {
+		defer file.Close()
+		scanner := bufio.NewScanner(file)
+		for scanner.Scan() {
+			line := scanner.Text()
+			if strings.HasPrefix(line, "MemTotal:") {
+				parts := strings.Fields(line)
+				if len(parts) >= 2 {
+					val, _ := strconv.ParseInt(parts[1], 10, 64)
+					result.Linux.MemTotal = val * 1024 // Convert KB to bytes
+				}
+			}
+			if strings.HasPrefix(line, "MemAvailable:") {
+				parts := strings.Fields(line)
+				if len(parts) >= 2 {
+					val, _ := strconv.ParseInt(parts[1], 10, 64)
+					result.Linux.MemAvailable = val * 1024 // Convert KB to bytes
+					// 4GB minimum available for large restores
+					result.Linux.MemAvailableOK = result.Linux.MemAvailable >= 4*1024*1024*1024
+				}
+			}
+		}
+	}
+
+	// Add warnings for insufficient resources
+	if !result.Linux.ShmMaxOK && result.Linux.ShmMax > 0 {
+		result.Warnings = append(result.Warnings,
+			fmt.Sprintf("Linux shmmax is low: %s (recommend 8GB+). Fix: sudo sysctl -w kernel.shmmax=17179869184",
+				formatBytesLong(result.Linux.ShmMax)))
+	}
+	if !result.Linux.ShmAllOK && result.Linux.ShmAll > 0 {
+		result.Warnings = append(result.Warnings,
+			fmt.Sprintf("Linux shmall is low: %d pages (recommend 2M+). Fix: sudo sysctl -w kernel.shmall=4194304",
+				result.Linux.ShmAll))
+	}
+	if !result.Linux.MemAvailableOK && result.Linux.MemAvailable > 0 {
+		result.Warnings = append(result.Warnings,
+			fmt.Sprintf("Available RAM is low: %s (recommend 4GB+ for large restores)",
+				formatBytesLong(result.Linux.MemAvailable)))
+	}
+}
+
+// checkPostgreSQL checks PostgreSQL configuration via SQL
+func (e *Engine) checkPostgreSQL(ctx context.Context, result *PreflightResult) {
+	connStr := e.buildConnString()
+	db, err := sql.Open("pgx", connStr)
+	if err != nil {
+		e.log.Warn("Could not connect to PostgreSQL for preflight checks", "error", err)
+		return
+	}
+	defer db.Close()
+
+	// Check max_locks_per_transaction
+	var maxLocks string
+	if err := db.QueryRowContext(ctx, "SHOW max_locks_per_transaction").Scan(&maxLocks); err == nil {
+		result.PostgreSQL.MaxLocksPerTransaction, _ = strconv.Atoi(maxLocks)
+	}
+
+	// Check maintenance_work_mem
+	db.QueryRowContext(ctx, "SHOW maintenance_work_mem").Scan(&result.PostgreSQL.MaintenanceWorkMem)
+
+	// Check shared_buffers (info only, can't change without restart)
+	db.QueryRowContext(ctx, "SHOW shared_buffers").Scan(&result.PostgreSQL.SharedBuffers)
+
+	// Check max_connections
+	var maxConn string
+	if err := db.QueryRowContext(ctx, "SHOW max_connections").Scan(&maxConn); err == nil {
+		result.PostgreSQL.MaxConnections, _ = strconv.Atoi(maxConn)
+	}
+
+	// Check version
+	db.QueryRowContext(ctx, "SHOW server_version").Scan(&result.PostgreSQL.Version)
+
+	// Check if superuser
+	var isSuperuser bool
+	if err := db.QueryRowContext(ctx, "SELECT current_setting('is_superuser') = 'on'").Scan(&isSuperuser); err == nil {
+		result.PostgreSQL.IsSuperuser = isSuperuser
+	}
+
+	// Add info/warnings
+	if result.PostgreSQL.MaxLocksPerTransaction < 256 {
+		e.log.Info("PostgreSQL max_locks_per_transaction is low - will auto-boost",
+			"current", result.PostgreSQL.MaxLocksPerTransaction)
+	}
+
+	// Parse shared_buffers and warn if very low
+	sharedBuffersMB := parseMemoryToMB(result.PostgreSQL.SharedBuffers)
+	if sharedBuffersMB > 0 && sharedBuffersMB < 256 {
+		result.Warnings = append(result.Warnings,
+			fmt.Sprintf("PostgreSQL shared_buffers is low: %s (recommend 1GB+, requires restart)",
+				result.PostgreSQL.SharedBuffers))
+	}
+}
+
+// analyzeArchive counts BLOBs in dump files to calculate optimal lock boost
+func (e *Engine) analyzeArchive(ctx context.Context, dumpsDir string, entries []os.DirEntry, result *PreflightResult) {
+	e.progress.Update("[PREFLIGHT] Analyzing archive for large objects...")
+
+	for _, entry := range entries {
+		if entry.IsDir() {
+			continue
+		}
+
+		result.Archive.TotalDatabases++
+		dumpFile := filepath.Join(dumpsDir, entry.Name())
+		dbName := strings.TrimSuffix(entry.Name(), ".dump")
+		dbName = strings.TrimSuffix(dbName, ".sql.gz")
+
+		// For custom format dumps, use pg_restore -l to count BLOBs
+		if strings.HasSuffix(entry.Name(), ".dump") {
+			blobCount := e.countBlobsInDump(ctx, dumpFile)
+			if blobCount > 0 {
+				result.Archive.BlobsByDB[dbName] = blobCount
+				result.Archive.TotalBlobCount += blobCount
+				if blobCount > 1000 {
+					result.Archive.HasLargeBlobs = true
+				}
+			}
+		}
+
+		// For SQL format, try to estimate from file content (sample check)
+		if strings.HasSuffix(entry.Name(), ".sql.gz") {
+			// Check for lo_create patterns in compressed SQL
+			blobCount := e.estimateBlobsInSQL(dumpFile)
+			if blobCount > 0 {
+				result.Archive.BlobsByDB[dbName] = blobCount
+				result.Archive.TotalBlobCount += blobCount
+				if blobCount > 1000 {
+					result.Archive.HasLargeBlobs = true
+				}
+			}
+		}
+	}
+}
+
+// countBlobsInDump uses pg_restore -l to count BLOB entries
+func (e *Engine) countBlobsInDump(ctx context.Context, dumpFile string) int {
+	ctx, cancel := context.WithTimeout(ctx, 30*time.Second)
+	defer cancel()
+
+	cmd := exec.CommandContext(ctx, "pg_restore", "-l", dumpFile)
+	output, err := cmd.Output()
+	if err != nil {
+		return 0
+	}
+
+	// Count lines containing BLOB/LARGE OBJECT
+	count := 0
+	for _, line := range strings.Split(string(output), "\n") {
+		if strings.Contains(line, "BLOB") || strings.Contains(line, "LARGE OBJECT") {
+			count++
+		}
+	}
+	return count
+}
+
+// estimateBlobsInSQL samples compressed SQL for lo_create patterns
+func (e *Engine) estimateBlobsInSQL(sqlFile string) int {
+	// Use zgrep for efficient searching in gzipped files
+	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+	defer cancel()
+
+	// Count lo_create calls (each = one large object)
+	cmd := exec.CommandContext(ctx, "zgrep", "-c", "lo_create", sqlFile)
+	output, err := cmd.Output()
+	if err != nil {
+		// Also try SELECT lo_create pattern
+		cmd2 := exec.CommandContext(ctx, "zgrep", "-c", "SELECT.*lo_create", sqlFile)
+		output, err = cmd2.Output()
+		if err != nil {
+			return 0
+		}
+	}
+
+	count, _ := strconv.Atoi(strings.TrimSpace(string(output)))
+	return count
+}
+
+// calculateRecommendations determines optimal settings based on analysis
+func (e *Engine) calculateRecommendations(result *PreflightResult) {
+	// Base lock boost
+	lockBoost := 2048
+
+	// Scale up based on BLOB count
+	if result.Archive.TotalBlobCount > 5000 {
+		lockBoost = 4096
+	}
+	if result.Archive.TotalBlobCount > 10000 {
+		lockBoost = 8192
+	}
+	if result.Archive.TotalBlobCount > 50000 {
+		lockBoost = 16384
+	}
+
+	// Cap at reasonable maximum
+	if lockBoost > 16384 {
+		lockBoost = 16384
+	}
+
+	result.Archive.RecommendedLockBoost = lockBoost
+
+	// Log recommendation
+	e.log.Info("Calculated recommended lock boost",
+		"total_blobs", result.Archive.TotalBlobCount,
+		"recommended_locks", lockBoost)
+}
+
+// printPreflightSummary prints a nice summary of all checks
+func (e *Engine) printPreflightSummary(result *PreflightResult) {
+	fmt.Println()
+	fmt.Println(strings.Repeat("─", 60))
+	fmt.Println("                    PREFLIGHT CHECKS")
+	fmt.Println(strings.Repeat("─", 60))
+
+	// Linux checks
+	if result.Linux.IsLinux {
+		fmt.Println("\n  Linux System:")
+		printCheck("shmmax", formatBytesLong(result.Linux.ShmMax), result.Linux.ShmMaxOK || result.Linux.ShmMax == 0)
+		printCheck("shmall", fmt.Sprintf("%d pages", result.Linux.ShmAll), result.Linux.ShmAllOK || result.Linux.ShmAll == 0)
+		printCheck("Available RAM", formatBytesLong(result.Linux.MemAvailable), result.Linux.MemAvailableOK || result.Linux.MemAvailable == 0)
+	}
+
+	// PostgreSQL checks
+	fmt.Println("\n  PostgreSQL:")
+	printCheck("Version", result.PostgreSQL.Version, true)
+	printCheck("max_locks_per_transaction", fmt.Sprintf("%d → %d (auto-boost)",
+		result.PostgreSQL.MaxLocksPerTransaction, result.Archive.RecommendedLockBoost),
+		true)
+	printCheck("maintenance_work_mem", fmt.Sprintf("%s → 2GB (auto-boost)",
+		result.PostgreSQL.MaintenanceWorkMem), true)
+	printInfo("shared_buffers", result.PostgreSQL.SharedBuffers)
+	printCheck("Superuser", fmt.Sprintf("%v", result.PostgreSQL.IsSuperuser), result.PostgreSQL.IsSuperuser)
+
+	// Archive analysis
+	fmt.Println("\n  Archive Analysis:")
+	printInfo("Total databases", fmt.Sprintf("%d", result.Archive.TotalDatabases))
+	printInfo("Total BLOBs detected", fmt.Sprintf("%d", result.Archive.TotalBlobCount))
+	if len(result.Archive.BlobsByDB) > 0 {
+		fmt.Println("    Databases with BLOBs:")
+		for db, count := range result.Archive.BlobsByDB {
+			status := "✓"
+			if count > 1000 {
+				status = "⚠"
+			}
+			fmt.Printf("      %s %s: %d BLOBs\n", status, db, count)
+		}
+	}
+
+	// Warnings
+	if len(result.Warnings) > 0 {
+		fmt.Println("\n  ⚠ Warnings:")
+		for _, w := range result.Warnings {
+			fmt.Printf("    • %s\n", w)
+		}
+	}
+
+	fmt.Println(strings.Repeat("─", 60))
+	fmt.Println()
+}
+
+func printCheck(name, value string, ok bool) {
+	status := "✓"
+	if !ok {
+		status = "⚠"
+	}
+	fmt.Printf("    %s %s: %s\n", status, name, value)
+}
+
+func printInfo(name, value string) {
+	fmt.Printf("    ℹ %s: %s\n", name, value)
+}
+
+// formatBytesLong is a local formatting helper for preflight display
+func formatBytesLong(bytes int64) string {
+	if bytes == 0 {
+		return "unknown"
+	}
+	const unit = 1024
+	if bytes < unit {
+		return fmt.Sprintf("%d B", bytes)
+	}
+	div, exp := int64(unit), 0
+	for n := bytes / unit; n >= unit; n /= unit {
+		div *= unit
+		exp++
+	}
+	return fmt.Sprintf("%.1f %cB", float64(bytes)/float64(div), "KMGTPE"[exp])
+}
+
+func parseMemoryToMB(memStr string) int {
+	memStr = strings.ToUpper(strings.TrimSpace(memStr))
+	var value int
+	var unit string
+	fmt.Sscanf(memStr, "%d%s", &value, &unit)
+
+	switch {
+	case strings.HasPrefix(unit, "G"):
+		return value * 1024
+	case strings.HasPrefix(unit, "M"):
+		return value
+	case strings.HasPrefix(unit, "K"):
+		return value / 1024
+	default:
+		return value / (1024 * 1024) // Assume bytes
+	}
+}
+
+func (e *Engine) buildConnString() string {
+	if e.cfg.Host == "localhost" || e.cfg.Host == "" {
+		return fmt.Sprintf("user=%s password=%s dbname=postgres sslmode=disable",
+			e.cfg.User, e.cfg.Password)
+	}
+	return fmt.Sprintf("host=%s port=%d user=%s password=%s dbname=postgres sslmode=disable",
+		e.cfg.Host, e.cfg.Port, e.cfg.User, e.cfg.Password)
+}