feat: add Server Dashboard & Activity Monitor (#658)

* feat: add Server Dashboard with active sessions, metrics, and slow query monitoring

* fix: address review feedback for server dashboard

* fix: show "Server Dashboard" in toolbar title instead of "SQL Query"

* fix: filter out PostgreSQL background workers from dashboard sessions

* fix: address 11 review issues in server dashboard

* fix: skip dashboard refresh silently when connection not ready yet

* docs: add server dashboard page to navigation

* docs: add screenshot placeholders to server dashboard page

* wip

Author: datlechin

CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+
+- Server Dashboard with active sessions, server metrics, and slow query monitoring (PostgreSQL, MySQL, MSSQL, ClickHouse, DuckDB, SQLite)
+
 ## [0.30.1] - 2026-04-10
 
 ### Added

TablePro/ContentView.swift

@@ -37,7 +37,9 @@ struct ContentView: View {
     init(payload: EditorTabPayload?) {
         self.payload = payload
         let defaultTitle: String
-        if let tableName = payload?.tableName {
+        if payload?.tabType == .serverDashboard {
+            defaultTitle = String(localized: "Server Dashboard")
+        } else if let tableName = payload?.tableName {
             defaultTitle = tableName
         } else if let connectionId = payload?.connectionId,
                   let connection = DatabaseManager.shared.activeSessions[connectionId]?.connection {

TablePro/Core/ServerDashboard/Providers/ClickHouseDashboardProvider.swift

@@ -0,0 +1,157 @@
+//
+//  ClickHouseDashboardProvider.swift
+//  TablePro
+//
+
+import Foundation
+
+struct ClickHouseDashboardProvider: ServerDashboardQueryProvider {
+    let supportedPanels: Set<DashboardPanel> = [.activeSessions, .serverMetrics, .slowQueries]
+
+    func fetchSessions(execute: (String) async throws -> QueryResult) async throws -> [DashboardSession] {
+        let sql = """
+            SELECT query_id, user, current_database, elapsed, read_rows,
+                   memory_usage, left(query, 1000) AS query
+            FROM system.processes
+            ORDER BY elapsed DESC
+            """
+        let result = try await execute(sql)
+        let col = columnIndex(from: result.columns)
+        return result.rows.map { row in
+            let elapsed = Double(value(row, at: col["elapsed"])) ?? 0
+            let readRows = value(row, at: col["read_rows"])
+            let memUsage = value(row, at: col["memory_usage"])
+            let stateDescription = "rows: \(readRows), mem: \(formatBytes(memUsage))"
+            let secs = Int(elapsed)
+            return DashboardSession(
+                id: value(row, at: col["query_id"]),
+                user: value(row, at: col["user"]),
+                database: value(row, at: col["current_database"]),
+                state: stateDescription,
+                durationSeconds: secs,
+                duration: formatDuration(seconds: secs),
+                query: value(row, at: col["query"]),
+                canCancel: false
+            )
+        }
+    }
+
+    func fetchMetrics(execute: (String) async throws -> QueryResult) async throws -> [DashboardMetric] {
+        var metrics: [DashboardMetric] = []
+
+        let metricsResult = try await execute("""
+            SELECT metric, value FROM system.metrics
+            WHERE metric IN ('Query', 'Merge', 'PartMutation')
+            """)
+        let col = columnIndex(from: metricsResult.columns)
+        for row in metricsResult.rows {
+            let metric = value(row, at: col["metric"])
+            let val = value(row, at: col["value"])
+            let (label, icon) = metricDisplay(for: metric)
+            metrics.append(DashboardMetric(
+                id: metric.lowercased(),
+                label: label,
+                value: val,
+                unit: "",
+                icon: icon
+            ))
+        }
+
+        let diskResult = try await execute("""
+            SELECT formatReadableSize(sum(bytes_on_disk)) AS disk_usage
+            FROM system.parts WHERE active
+            """)
+        if let row = diskResult.rows.first {
+            metrics.append(DashboardMetric(
+                id: "disk_usage",
+                label: String(localized: "Disk Usage"),
+                value: value(row, at: 0),
+                unit: "",
+                icon: "internaldrive"
+            ))
+        }
+
+        return metrics
+    }
+
+    func fetchSlowQueries(execute: (String) async throws -> QueryResult) async throws -> [DashboardSlowQuery] {
+        let sql = """
+            SELECT user, query_duration_ms / 1000 AS duration_secs,
+                   left(query, 1000) AS query
+            FROM system.query_log
+            WHERE type = 'QueryFinish' AND query_duration_ms > 1000
+            ORDER BY event_time DESC
+            LIMIT 20
+            """
+        let result = try await execute(sql)
+        let col = columnIndex(from: result.columns)
+        return result.rows.map { row in
+            let secs = Int(value(row, at: col["duration_secs"])) ?? 0
+            return DashboardSlowQuery(
+                duration: formatDuration(seconds: secs),
+                query: value(row, at: col["query"]),
+                user: value(row, at: col["user"]),
+                database: ""
+            )
+        }
+    }
+
+    func killSessionSQL(processId: String) -> String? {
+        let uuidPattern = #"^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$"#
+        guard processId.range(of: uuidPattern, options: [.regularExpression, .caseInsensitive]) != nil else {
+            return nil
+        }
+        return "KILL QUERY WHERE query_id = '\(processId)'"
+    }
+}
+
+// MARK: - Helpers
+
+private extension ClickHouseDashboardProvider {
+    func columnIndex(from columns: [String]) -> [String: Int] {
+        var map: [String: Int] = [:]
+        for (index, name) in columns.enumerated() {
+            map[name.lowercased()] = index
+        }
+        return map
+    }
+
+    func value(_ row: [String?], at index: Int?) -> String {
+        guard let index, index < row.count else { return "" }
+        return row[index] ?? ""
+    }
+
+    func formatDuration(seconds: Int) -> String {
+        if seconds >= 3_600 {
+            return "\(seconds / 3_600)h \((seconds % 3_600) / 60)m"
+        } else if seconds >= 60 {
+            return "\(seconds / 60)m \(seconds % 60)s"
+        }
+        return "\(seconds)s"
+    }
+
+    func formatBytes(_ string: String) -> String {
+        guard let bytes = Double(string) else { return string }
+        if bytes >= 1_073_741_824 {
+            return String(format: "%.1f GB", bytes / 1_073_741_824)
+        } else if bytes >= 1_048_576 {
+            return String(format: "%.1f MB", bytes / 1_048_576)
+        } else if bytes >= 1_024 {
+            return String(format: "%.1f KB", bytes / 1_024)
+        }
+        return "\(Int(bytes)) B"
+    }
+
+    func metricDisplay(for metric: String) -> (String, String) {
+        switch metric {
+        case "Query":
+            return (String(localized: "Active Queries"), "bolt.horizontal")
+        case "Merge":
+            return (String(localized: "Active Merges"), "arrow.triangle.merge")
+        case "PartMutation":
+            return (String(localized: "Part Mutations"), "gearshape.2")
+        default:
+            return (metric, "chart.bar")
+        }
+    }
+}

TablePro/Core/ServerDashboard/Providers/DuckDBDashboardProvider.swift

@@ -0,0 +1,98 @@
+//
+//  DuckDBDashboardProvider.swift
+//  TablePro
+//
+
+import Foundation
+
+struct DuckDBDashboardProvider: ServerDashboardQueryProvider {
+    let supportedPanels: Set<DashboardPanel> = [.serverMetrics]
+
+    func fetchMetrics(execute: (String) async throws -> QueryResult) async throws -> [DashboardMetric] {
+        var metrics: [DashboardMetric] = []
+
+        let sizeResult = try await execute("SELECT * FROM pragma_database_size()")
+        if let row = sizeResult.rows.first {
+            let col = columnIndex(from: sizeResult.columns)
+            let dbSize = value(row, at: col["database_size"])
+            let blockSize = value(row, at: col["block_size"])
+            let totalBlocks = value(row, at: col["total_blocks"])
+
+            if !dbSize.isEmpty {
+                metrics.append(DashboardMetric(
+                    id: "db_size",
+                    label: String(localized: "Database Size"),
+                    value: dbSize,
+                    unit: "",
+                    icon: "internaldrive"
+                ))
+            }
+            if !blockSize.isEmpty {
+                metrics.append(DashboardMetric(
+                    id: "block_size",
+                    label: String(localized: "Block Size"),
+                    value: blockSize,
+                    unit: "",
+                    icon: "square.grid.3x3"
+                ))
+            }
+            if !totalBlocks.isEmpty {
+                metrics.append(DashboardMetric(
+                    id: "total_blocks",
+                    label: String(localized: "Total Blocks"),
+                    value: totalBlocks,
+                    unit: "",
+                    icon: "cube"
+                ))
+            }
+        }
+
+        let settingsResult = try await execute("""
+            SELECT current_setting('memory_limit') AS memory_limit,
+                   current_setting('threads') AS threads
+            """)
+        if let row = settingsResult.rows.first {
+            let col = columnIndex(from: settingsResult.columns)
+            let memLimit = value(row, at: col["memory_limit"])
+            let threads = value(row, at: col["threads"])
+
+            if !memLimit.isEmpty {
+                metrics.append(DashboardMetric(
+                    id: "memory_limit",
+                    label: String(localized: "Memory Limit"),
+                    value: memLimit,
+                    unit: "",
+                    icon: "memorychip"
+                ))
+            }
+            if !threads.isEmpty {
+                metrics.append(DashboardMetric(
+                    id: "threads",
+                    label: String(localized: "Threads"),
+                    value: threads,
+                    unit: "",
+                    icon: "cpu"
+                ))
+            }
+        }
+
+        return metrics
+    }
+}
+
+// MARK: - Helpers
+
+private extension DuckDBDashboardProvider {
+    func columnIndex(from columns: [String]) -> [String: Int] {
+        var map: [String: Int] = [:]
+        for (index, name) in columns.enumerated() {
+            map[name.lowercased()] = index
+        }
+        return map
+    }
+
+    func value(_ row: [String?], at index: Int?) -> String {
+        guard let index, index < row.count else { return "" }
+        return row[index] ?? ""
+    }
+}