--- a/plugins/mod_storage_sql.lua	Mon Mar 21 12:10:10 2016 +0100
+++ b/plugins/mod_storage_sql.lua	Mon Mar 21 14:52:43 2016 +0100
@@ -82,16 +82,14 @@
 		local extradata = {};
 		for key, value in pairs(data) do
 			if type(key) == "string" and key ~= "" then
-				local t, value = serialize(value);
-				assert(t, value);
+				local t, value = assert(serialize(value));
 				engine:insert("INSERT INTO `prosody` (`host`,`user`,`store`,`key`,`type`,`value`) VALUES (?,?,?,?,?,?)", host, user or "", store, key, t, value);
 			else
 				extradata[key] = value;
 			end
 		end
 		if next(extradata) ~= nil then
-			local t, extradata = serialize(extradata);
-			assert(t, extradata);
+			local t, extradata = assert(serialize(extradata));
 			engine:insert("INSERT INTO `prosody` (`host`,`user`,`store`,`key`,`type`,`value`) VALUES (?,?,?,?,?,?)", host, user or "", store, "", t, extradata);
 		end
 	end
@@ -197,7 +195,7 @@
 		else
 			key = uuid.generate();
 		end
-		local t, value = serialize(value);
+		local t, value = assert(serialize(value));
 		engine:insert("INSERT INTO `prosodyarchive` (`host`, `user`, `store`, `when`, `with`, `key`, `type`, `value`) VALUES (?,?,?,?,?,?,?,?)", host, user or "", store, when, with, key, t, value);
 		return key;
 	end);

--- a/util/sql.lua	Mon Mar 21 12:10:10 2016 +0100
+++ b/util/sql.lua	Mon Mar 21 14:52:43 2016 +0100
@@ -102,11 +102,12 @@
 	local params = self.params;
 	assert(params.driver, "no driver")
 	log("debug", "Connecting to [%s] %s...", params.driver, params.database);
-	local dbh, err = DBI.Connect(
+	local ok, dbh, err = pcall(DBI.Connect,
 		params.driver, params.database,
 		params.username, params.password,
 		params.host, params.port
 	);
+	if not ok then return ok, dbh; end
 	if not dbh then return nil, err; end
 	dbh:autocommit(false); -- don't commit automatically
 	self.conn = dbh;