diff --git a/tools/chatgui/db/db_manager.cpp b/tools/chatgui/db/db_manager.cpp
index 74095b19..90d0ec7a 100644
--- a/tools/chatgui/db/db_manager.cpp
+++ b/tools/chatgui/db/db_manager.cpp
@@ -700,6 +700,9 @@ QByteArray DbManager::syncListPeers(const QString& chId) const {
 
 /* ── integrity checks ── */
 
+enum class PragmaMode { IntegrityCheck, Command };
+
+/* SQLite сообщает нарушения целостности строками даже при SQLITE_OK; сохраняем первое и дополнительные сообщения. */
 static int integrityCallback(void* data, int nCols, char** values, char** /*names*/) {
     auto* result = (IntegrityResult*)data;
     for (int i = 0; i < nCols; i++) {
@@ -712,37 +715,55 @@ static int integrityCallback(void* data, int nCols, char** values, char** /*name
     return 0;
 }
 
-static IntegrityResult runPragma(DbManager* self, const char* pragma) {
+/* Проверки требуют ответа ok; у команды обслуживания успех определяется завершением SQL, без обязательных строк. */
+static IntegrityResult runPragma(sqlite3* db, const char* pragma, PragmaMode mode) {
     IntegrityResult result;
-    if (!self->m_db) {
-        result.ok = false;
+    DEBUG_DEBUG(DEBUG_CATEGORY_CONFIG, "DB maintenance begin operation=%s db=%p integrity=%d",
+                pragma, static_cast<void*>(db), mode == PragmaMode::IntegrityCheck);
+    if (!db) {
         result.message = "Database not open";
+        DEBUG_ERROR(DEBUG_CATEGORY_CONFIG, "DB maintenance failed operation=%s: database not open", pragma);
         return result;
     }
     QElapsedTimer timer;
     timer.start();
     char* errMsg = nullptr;
-    int rc = sqlite3_exec(self->m_db, pragma, integrityCallback, &result, &errMsg);
+    const int rc = sqlite3_exec(db, pragma, mode == PragmaMode::IntegrityCheck ? integrityCallback : nullptr, &result, &errMsg);
     result.elapsedMs = (int)timer.elapsed();
     if (rc != SQLITE_OK) {
-        result.ok = false;
-        result.message = QString::fromUtf8(errMsg ? errMsg : "unknown error");
+        result.message = QString::fromUtf8(errMsg ? errMsg : sqlite3_errmsg(db));
+        DEBUG_ERROR(DEBUG_CATEGORY_CONFIG, "DB maintenance failed operation=%s rc=%d elapsed=%dms: %s",
+                    pragma, rc, result.elapsedMs, qPrintable(result.message));
         sqlite3_free(errMsg);
         return result;
     }
-    if (errMsg) sqlite3_free(errMsg);
-    result.ok = (result.message == "ok" && result.errors.isEmpty());
+    sqlite3_free(errMsg);
+    if (mode == PragmaMode::Command) {
+        result.ok = true;
+        result.message = "ok";
+    } else {
+        result.ok = result.message == "ok" && result.errors.isEmpty();
+        if (result.message.isEmpty()) result.message = "Integrity check returned no result";
+    }
+    if (result.ok) {
+        DEBUG_INFO(DEBUG_CATEGORY_CONFIG, "DB maintenance complete operation=%s rc=%d elapsed=%dms result=ok", pragma, rc, result.elapsedMs);
+    } else {
+        DEBUG_ERROR(DEBUG_CATEGORY_CONFIG, "DB maintenance failed operation=%s rc=%d elapsed=%dms extra_errors=%d: %s",
+                    pragma, rc, result.elapsedMs, int(result.errors.size()), qPrintable(result.message));
+        for (const auto& error : result.errors)
+            DEBUG_ERROR(DEBUG_CATEGORY_CONFIG, "DB maintenance detail operation=%s: %s", pragma, qPrintable(error));
+    }
     return result;
 }
 
 IntegrityResult DbManager::integrityCheckQuick() const {
-    return runPragma(const_cast<DbManager*>(this), "PRAGMA quick_check");
+    return runPragma(m_db, "PRAGMA quick_check", PragmaMode::IntegrityCheck);
 }
 
 IntegrityResult DbManager::integrityCheckFull() const {
-    return runPragma(const_cast<DbManager*>(this), "PRAGMA integrity_check");
+    return runPragma(m_db, "PRAGMA integrity_check", PragmaMode::IntegrityCheck);
 }
 
 IntegrityResult DbManager::integrityOptimize() const {
-    return runPragma(const_cast<DbManager*>(this), "PRAGMA optimize");
+    return runPragma(m_db, "PRAGMA optimize", PragmaMode::Command);
 }
diff --git a/tools/chatgui/db/db_manager.h b/tools/chatgui/db/db_manager.h
index cac53f08..dd895a8f 100644
--- a/tools/chatgui/db/db_manager.h
+++ b/tools/chatgui/db/db_manager.h
@@ -69,11 +69,12 @@ struct NodeAddr {
     int        socketId = 0;            // socket_id из ETCP
 };
 
+/* Результат синхронной проверки/обслуживания SQLite; успех optimize не подтверждает целостность данных. */
 struct IntegrityResult {
-    bool        ok = false;
-    QString     message;
-    QStringList errors;
-    int         elapsedMs = 0;
+    bool        ok = false; // Проверка: SQL успешен и получен ok без нарушений; optimize: SQL завершён успешно.
+    QString     message; // ok при успехе, иначе первая диагностика проверки либо ошибка SQL/отсутствия БД.
+    QStringList errors; // Дополнительные сообщения integrity-проверки после первого.
+    int         elapsedMs = 0; // Время SQL-вызова, мс; 0 также при отсутствии handle.
 };
 
 struct DmConversation {
@@ -160,9 +161,10 @@ public:
     static QString sanitizeTableName(const QString& chId);
     static uint64_t computeDatahash(const QByteArray& data);
 
-    IntegrityResult integrityCheckQuick() const;
-    IntegrityResult integrityCheckFull() const;
-    IntegrityResult integrityOptimize() const;
+    /* Синхронные PRAGMA на заимствованном handle; вызывающий сохраняет его живым до возврата, ошибки логируются в CONFIG. */
+    IntegrityResult integrityCheckQuick() const; // quick_check: требует ответ ok, нарушения в строках SQLite означают отказ.
+    IntegrityResult integrityCheckFull() const; // integrity_check: тот же контракт, полная проверка со сверкой индексов.
+    IntegrityResult integrityOptimize() const; // optimize: SQL-успех допустим без строк результата; не является integrity-проверкой.
 
     sqlite3* m_db = nullptr;
     QString  m_dbPath;
diff --git a/tools/chatgui/tests/test_database_maintenance.cpp b/tools/chatgui/tests/test_database_maintenance.cpp
index 5f8d8dde..fe2c599e 100644
--- a/tools/chatgui/tests/test_database_maintenance.cpp
+++ b/tools/chatgui/tests/test_database_maintenance.cpp
@@ -10,7 +10,7 @@ extern "C" {
 using Operation = IntegrityResult (DbManager::*)() const;
 static const Operation operations[] = {&DbManager::integrityCheckQuick, &DbManager::integrityCheckFull, &DbManager::integrityOptimize};
 static const char* titles[] = {"Quick Check", "Full Check", "Optimize"};
-static const char* slots[] = {"onQuickCheck", "onFullCheck", "onOptimize"};
+static const char* actionSlots[] = {"onQuickCheck", "onFullCheck", "onOptimize"};
 
 struct Database {
     QTemporaryDir directory;
@@ -112,14 +112,15 @@ private slots:
         QTest::addColumn<int>("operation"); QTest::addColumn<bool>("denied");
         for (int operation = 0; operation < 3; ++operation)
             for (bool denied : {false, true})
-                QTest::newRow(qPrintable(QString("%1-%2").arg(titles[operation]).arg(denied ? "denied" : "success"))) << operation << denied;
+                QTest::newRow(qPrintable(QString("%1-%2").arg(titles[operation]).arg(denied ? "denied" : "success")))
+                    << operation << denied;
     }
     void pageShowsResult() {
         QFETCH(int, operation); QFETCH(bool, denied);
         Database db; QVERIFY(db.open());
         DatabaseSettingsPage page(&db.manager);
         if (denied) QCOMPARE(sqlite3_set_authorizer(db.handle, denyPragma, nullptr), SQLITE_OK);
-        QVERIFY(QMetaObject::invokeMethod(&page, slots[operation], Qt::DirectConnection));
+        QVERIFY(QMetaObject::invokeMethod(&page, actionSlots[operation], Qt::DirectConnection));
         const auto buttons = page.findChildren<QPushButton*>(); QCOMPARE(buttons.size(), 3);
         for (auto* button : buttons) QVERIFY(!button->isEnabled());
         QTRY_VERIFY_WITH_TIMEOUT(!statusText(page).isEmpty(), 1000);