Added a db migrate module.

diff --git a/src/highscore.lua b/src/highscore.lua
index fc673ca..f52b047 100644
--- a/src/highscore.lua
+++ b/src/highscore.lua
@@ -25,7 +25,7 @@ addon.highscore = highscore;
 -- db defaults
 addon.dbDefaults.realm.modules["highscore"] = {
 	["guilds"] = {
-		["*"] = { -- Guild Name
+		["*"] = { -- guildName
 			["zones"] = {
 				["*"] = { -- zoneId
 					["difficulties"] = {
@@ -79,14 +79,18 @@ addon.dbDefaults.realm.modules["highscore"] = {
 		-- keys. We have to be able to test for existence.
 		--[[
 		["*"] = { -- groupParseId
-			startTime 	= 0,
-			duration 	= 0,
+			startTime    = 0,
+			duration     = 0,
+			guildName    = "",
+			zoneId       = 0,
+			difficultyId = 0,
+			encounterId  = 0,
 		}
 		--]]
 	}
 }

-addon.dbVersion = addon.dbVersion + 5
+addon.dbVersion = addon.dbVersion + 6;

 -- Constants
 local TRACKED_ZONE_IDS = {
@@ -358,6 +362,21 @@ function highscore:GetGuildNameById(guildId)
 	return guildId;
 end

+-- Removes parses that is older than "olderThanDate". If minParsesPerPlayer
+-- is > 0, that many parses will be kept for the player/encounter combination.
+function highscore:PurgeParses(olderThanDate, minParsesPerPlayer)
+	local oldGroupParseIds = {};
+
+	for id, groupParse in pairs(self.db.groupParses) do
+		if groupParse.startTime < olderThanDate then
+			tinsert(oldGroupParseIds, id);
+		end
+	end
+
+	for _, id in ipairs(oldGroupParseIds) do
+
+	end
+end

 function highscore:OnEnable()
 	self.db = addon.db.realm.modules["highscore"];
diff --git a/src/main.lua b/src/main.lua
index dfa6c26..01b8158 100644
--- a/src/main.lua
+++ b/src/main.lua
@@ -33,16 +33,14 @@ addon:SetDefaultModulePrototype(modPrototype)
 addon.dbDefaults = {
 	realm = {
 		modules = {},
-		options = {}
-	},
-	global = {
+		options = {},
 		dbVersion = 1
-	}
+	},
 }

 -- The current db version. Clear (migrate?) the database if
 -- version of database doesn't match this version.
-addon.dbVersion = 2;
+addon.dbVersion = 3;

 -- Constants
 DEBUG_PRINT = false;
@@ -177,13 +175,7 @@ function addon:OnInitialize()
 	self.db = LibStub("AceDB-3.0"):New("GuildSkadaHighScoreDB", addon.dbDefaults, true)

 	-- Make sure db version is in sync
-	if self.db.global.dbVersion ~= self.dbVersion then
-		self:Debug(format("Found not matching db versions: db=%d, addon=%d",
-			self.db.global.dbVersion, self.dbVersion));
-		self:Debug("Resetting db");
-		self.db:ResetDB();
-		self.db.global.dbVersion = self.dbVersion;
-	end
+	self.migrate:DoMigration();
 end

 function addon:OnEnable()
diff --git a/src/migrate.lua b/src/migrate.lua
new file mode 100644
index 0000000..b58c5ad
--- /dev/null
+++ b/src/migrate.lua
@@ -0,0 +1,99 @@
+--
+-- migrate.lua
+--
+-- Contains database migration
+--
+
+local addonName, addonTable = ...
+
+-- Global functions for faster access
+local tinsert = tinsert;
+
+-- Set up module
+local addon = addonTable[1];
+local migrate = addon:NewModule("migrate");
+addon.migrate = migrate;
+
+
+local function migrate7to8(db)
+	-- dbVersion is now saved per realm, as every other
+	-- options is stored per realm.
+	local version = db.global.dbVersion;
+	db.realm.dbVersion = version;
+	return 8;
+end
+
+local function migrate8to9(db)
+	-- Each highscore groupParse should have the
+	-- guildName, zoneId, difficultyId and encounterId
+	-- it is associated with, so that it is possible to
+	-- find parses that is connected to a groupParse without
+	-- having to look trough all parses.
+
+	local highscoreDb = db.realm.modules["highscore"];
+
+	for guildName, guildData in pairs(highscoreDb.guilds) do
+		for zoneId, zoneData in pairs(guildData.zones) do
+			for diffId, diffData in pairs(zoneData.difficulties) do
+				for encId, encData in pairs(diffData.encounters) do
+					for _, parse in pairs(encData.playerParses) do
+						local groupParseId = parse.groupParseId;
+						local groupParse = highscoreDb.groupParses[groupParseId];
+						groupParse.guildName = guildName;
+						groupParse.zoneId = zoneId;
+						groupParse.difficultyId = diffId;
+						groupParse.encounterId = encId;
+					end
+				end
+			end
+		end
+	end
+	return 9;
+end
+
+local migrateTable = {
+	[7] = migrate7to8,
+	[8] = migrate8to9
+}
+
+local function resetDb()
+	self:Debug("Resetting db");
+	addon.db:ResetDB();
+end
+
+function migrate:DoMigration()
+	local db = addon.db;
+	local targetVersion = addon.dbVersion;
+
+	local currentVersion = 1;
+	if db.global.dbVersion then
+		-- dbVersion used to be stored in global
+		currentVersion = db.global.dbVersion;
+	end
+
+	if db.realm.dbVersion and db.realm.dbVersion > currentVersion then
+		currentVersion = db.realm.dbVersion
+	end
+
+	if currentVersion == targetVersion then
+		return;
+	end
+
+	self:Debug(format("Attempting to migrate from dbVersion: %d to %d.",
+		currentVersion, targetVersion));
+
+	while currentVersion < targetVersion do
+		local migrateFunction = migrateTable[currentVersion];
+		if migrateFunction then
+			currentVersion = migrateFunction(db);
+		else
+			self:Debug(format("Could not migrate from dbVersion: %d!", currentVersion));
+			resetDb();
+			break;
+		end
+	end
+
+	db.realm.dbVersion = targetVersion;
+	self:Debug(format("Migration to dbVersion: %d completed.",
+		targetVersion));
+end
diff --git a/src/src_include.xml b/src/src_include.xml
index 0bb3dfd..cb4905d 100644
--- a/src/src_include.xml
+++ b/src/src_include.xml
@@ -5,5 +5,6 @@
 	<Script file="gui.lua"/>
 	<Script file="report.lua"/>
 	<Script file="options.lua"/>
+	<Script file="migrate.lua"/>
 	<Include file="parse_modules\parse_modules_include.xml"/>
 </Ui>
\ No newline at end of file