diff --git a/Database/compiler.lua b/Database/compiler.lua
index bcb0c1c..5ab2553 100644
--- a/Database/compiler.lua
+++ b/Database/compiler.lua
@@ -9,6 +9,8 @@ local QuestieDB = QuestieLoader:ImportModule("QuestieDB")
 local QuestieLib = QuestieLoader:ImportModule("QuestieLib")
 ---@type l10n
 local l10n = QuestieLoader:ImportModule("l10n")
+---@type QuestiePluginAPI
+local QuestiePluginAPI = QuestieLoader:ImportModule("QuestiePluginAPI")
 
 --- COMPATIBILITY ---
 local WOW_PROJECT_ID = QuestieCompat.WOW_PROJECT_ID
@@ -1095,6 +1097,7 @@ function QuestieDBCompiler:Compile()
     print("\124cFFAAEEFF"..l10n("Questie DB update complete!"))
 
     Questie.db.global.dbCompiledExpansion = WOW_PROJECT_ID
+    Questie.db.global.dbCompiledPluginSignature = QuestiePluginAPI:GetLoadedSignature()
 
     if Questie.IsSoD then
         Questie.db.global.sod.dbCompiledOnVersion = QuestieLib:GetAddonVersionString()
@@ -1107,6 +1110,8 @@ function QuestieDBCompiler:Compile()
         Questie.db.global.dbIsCompiled = true
         Questie.db.global.dbCompiledCount = (Questie.db.global.dbCompiledCount or 0) + 1
     end
+
+    QuestieDBCompiler._isCompiling = false
 end
 
 function QuestieDBCompiler:ValidateNPCs()
diff --git a/Modules/Libs/QuestiePluginAPI.lua b/Modules/Libs/QuestiePluginAPI.lua
index a152996..6867e61 100644
--- a/Modules/Libs/QuestiePluginAPI.lua
+++ b/Modules/Libs/QuestiePluginAPI.lua
@@ -4,6 +4,28 @@ local QuestiePluginAPI = QuestieLoader:CreateModule("QuestiePluginAPI")
 QuestiePluginAPI.registeredPlugins = {}
 QuestiePluginAPI.loadedDBFlavor    = nil   -- set by the first DB plugin that calls FinishLoading
 QuestiePluginAPI.pendingPluginsCount = 0   -- count of plugins that have registered but not yet FinishedLoading
+QuestiePluginAPI.loadedDBVersions = {}
+
+local KNOWN_PLUGIN_ADDONS = {
+    WotLKDB = "Questie-X-WotLKDB",
+    ClassicDB = "Questie-X-ClassicDB",
+    TBCDB = "Questie-X-TBCDB",
+    Ascension = "Questie-X-AscensionDB",
+    AscensionDB = "Questie-X-AscensionDB",
+    Ebonhold = "Questie-X-EbonholdDB",
+    EbonholdDB = "Questie-X-EbonholdDB",
+    Valanior = "Questie-X-ValaniorDB",
+    ValaniorDB = "Questie-X-ValaniorDB",
+    RetailDB = "Questie-X-RetailDB",
+}
+
+local function GetPluginAddonVersion(pluginName, flavorKey)
+    local addonName = KNOWN_PLUGIN_ADDONS[flavorKey] or KNOWN_PLUGIN_ADDONS[pluginName] or pluginName
+    if GetAddOnMetadata then
+        return GetAddOnMetadata(addonName, "Version") or "unknown"
+    end
+    return "unknown"
+end
 
 --- Returns true if at least one DB plugin has fully loaded.
 ---@return boolean
@@ -27,6 +49,27 @@ function QuestiePluginAPI:GetLoadedFlavor()
     return self.loadedDBFlavor
 end
 
+--- Returns a stable signature for loaded DB plugin data.
+---@return string
+function QuestiePluginAPI:GetLoadedSignature()
+    local parts = {}
+    local pluginName, plugin = next(self.registeredPlugins)
+    while pluginName do
+        local version = self.loadedDBVersions[pluginName] or plugin.version or "pending"
+        local flavor = plugin.flavorKey or pluginName
+        local stats = plugin.stats or {}
+        parts[#parts + 1] = pluginName .. ":" .. flavor .. ":" .. version
+            .. ":Q" .. tostring(stats.QUEST or 0)
+            .. ":N" .. tostring(stats.NPC or 0)
+            .. ":O" .. tostring(stats.OBJECT or 0)
+            .. ":I" .. tostring(stats.ITEM or 0)
+        pluginName, plugin = next(self.registeredPlugins, pluginName)
+    end
+
+    table.sort(parts)
+    return table.concat(parts, "|")
+end
+
 ---@class QuestiePlugin
 local QuestiePlugin = {}
 QuestiePlugin.__index = QuestiePlugin
@@ -298,6 +341,10 @@ function QuestiePlugin:FinishLoading(flavorKey)
         QuestiePluginAPI.loadedDBFlavor = self.name
     end
 
+    self.flavorKey = flavorKey or self.name
+    self.version = GetPluginAddonVersion(self.name, self.flavorKey)
+    QuestiePluginAPI.loadedDBVersions[self.name] = self.version
+
     if not self.isFinished then
         self.isFinished = true
         QuestiePluginAPI.pendingPluginsCount = math.max(0, QuestiePluginAPI.pendingPluginsCount - 1)
diff --git a/Modules/QuestieInit.lua b/Modules/QuestieInit.lua
index 41f2a29..f06607f 100644
--- a/Modules/QuestieInit.lua
+++ b/Modules/QuestieInit.lua
@@ -383,9 +383,13 @@ QuestieInit.Stages[3] = function() -- run as a coroutine
     local waitStart = GetTime()
     Questie:Debug(Questie.DEBUG_CRITICAL, "[QuestieInit:Stage3] Waiting for plugins to register/finish. Initial pending: " .. QuestiePluginAPI.pendingPluginsCount)
 
-    -- Give other addons/scripts a moment to fire and register if they were waiting for PLAYER_LOGIN
-    while (GetTime() - waitStart < 1.0) do
-        coYield()
+    -- Give DB plugins a short grace period only when a plugin addon is enabled
+    -- but none has registered yet. Avoid adding a fixed one-second delay to
+    -- every login after plugins are already registered.
+    if QuestieServer:IsAnyDBPluginEnabled() and (not QuestiePluginAPI:IsAnyPluginLoaded()) then
+        while (GetTime() - waitStart < 1.0) do
+            coYield()
+        end
     end
 
     local timeout = 10
@@ -395,16 +399,26 @@ QuestieInit.Stages[3] = function() -- run as a coroutine
         elapsed = GetTime() - waitStart
     end
 
-    -- Always re-compile on custom servers to pick up QuestieLearner changes from SavedVariables,
-    -- or if compilation was explicitly deferred/needed.
+    -- Recompile custom-server/plugin data only when the compiled cache no longer
+    -- matches the loaded plugin set. Learner data is applied as live overrides and
+    -- does not require rebuilding the binary DB cache on every login.
     local isCustomServer = Questie.IsAscension or Questie.IsEbonhold or Questie.IsValanior or QuestieServer:IsAnyDBPluginEnabled()
-    if isCustomServer or needsCompilation or (not Questie.db.global.dbIsCompiled) then
+    local pluginSignature = QuestiePluginAPI:GetLoadedSignature()
+    local cacheMatchesPlugins = Questie.db.global.dbCompiledPluginSignature == pluginSignature
+    local cacheMatchesCore = Questie.db.global.dbIsCompiled
+        and (QuestieLib:GetAddonVersionString() == Questie.db.global.dbCompiledOnVersion)
+        and (l10n:GetUILocale() == Questie.db.global.dbCompiledLang)
+        and (Questie.db.global.dbCompiledExpansion == WOW_PROJECT_ID)
+
+    if needsCompilation or (not cacheMatchesCore) or (isCustomServer and (not cacheMatchesPlugins)) then
         Questie:Debug(Questie.DEBUG_CRITICAL, "[QuestieInit:Stage3] Starting compilation (Server=" .. tostring(isCustomServer) .. ", Needed=" .. tostring(needsCompilation) .. ")")
         if not QuestieDB.questData then
             loadFullDatabase()
         end
         QuestieDBCompiler:Compile()
         QuestieDB:Initialize()
+    else
+        Questie:Debug(Questie.DEBUG_INFO, "[QuestieInit:Stage3] DB cache is current; skipping compilation.")
     end
 
     -- register events that rely on questie being initialized