Receiving a statement including requests for database operations in a secondary database system storing data replicated from a primary database system by replaying transaction output generated by the primary database system; responsive to receiving the statement, requesting an allocation of memory from the secondary database system to support the requested database operations; generating an aggregated statement memory consumption value based on the amount of memory consumed by all statements executing in the secondary database system that are not associated with replaying the transaction logs; determining that the requested allocation of memory in addition to the aggregated statement memory consumption value exceeds a total statement execution memory limit indicating a total amount of memory that may be allocated to all database operations associated with statement execution in a secondary database system, and denying the requested allocation of memory. Related apparatus, systems, techniques and articles are also described.