Update Doku aus Driversourcen

Change-Id: I455f0813b970151089b3dc1b8d9407eea323cdd1
diff --git a/doc/concepts/mysql b/doc/concepts/mysql
index 4fb6dee..66f4e7d 100644
--- a/doc/concepts/mysql
+++ b/doc/concepts/mysql
@@ -1,5 +1,5 @@
 CONCEPT
-            mysql - mySQL support
+        mysql - mySQL support
 
 DESCRIPTION
         On hosts with the mySQL package installed, the driver can be
@@ -12,9 +12,9 @@
         Create a dedicated user in the mySQL database for the driver.
         Enter this username and password in the file pkg-mysql.c, function
         mysql_real_connect(), and compile the driver (the username and
-        password are built into the driver for security reasons).
-        If you chose to not create either a username and/or a password,
-        leave the corresponding entry at 0.
+        password are built into the driver for security reasons). If you
+        choose to not create either a username and/or a password, leave the
+        corresponding entry at 0.
 
         Use mysqladmin to create any databases you want to provide - the
         names are later used in the efun db_connect() to connect to
@@ -32,7 +32,7 @@
 
         To connect to your mySQL-server, use the efun db_connect(). It
         takes only one argument which is the name of the database (which
-        must exist).  The return-value of db_connect() is an integer
+        must exist). The return-value of db_connect() is an integer
         representing the unique handle to the database with which you will
         identify your connection later.
 
@@ -94,6 +94,16 @@
           db_conv_string()
 
 
+        -- Caveats --
+
+        The driver enables automatic reconnects on the database connections.
+        This means that if a connection is lost - the most common case for
+        this is timeouts, which by default happen after 28800 seconds of
+        inactivity - an attempt will be made to establish a new connection to
+        the database server. When that happens, all session state (temprary
+        tables and state changes from SET statements) will be lost. It's best
+        not to rely on such state.
+
 EXAMPLE
         A simple server to store aliases could be implemented like this: