A computer implemented method for initializing a first image of a first database from a recovery image; modifying the first image of the first database by replaying transaction logs of a second database; establishing a connection with a client; receiving a query via the connection, the query including a transaction to be executed on the first database; and rejecting the query when the transaction would cause any one of: updating of the first image of the first database; generating a new transaction log; and modifying the recovery image. Related apparatus, systems, techniques and articles are also described.