Which parameters should be set to protect an SAP HANA database system against uncontrolled queries that consume excessive memory?

The parameter that should be set to protect an SAP HANA database system against uncontrolled queries that consume excessive memory is the statement_memory_limit. This parameter specifies the maximum amount of memory that can be consumed by an individual statement during its execution. By configuring this limit, database administrators can prevent any single query from monopolizing system resources, which can lead to performance degradation and affect the overall stability of the database.

Setting the statement_memory_limit plays a crucial role in managing resource allocation, especially in environments where large data sets are processed or complex queries are frequent. When a query attempts to exceed this defined memory limit, SAP HANA will terminate the execution of that query, thus safeguarding the system's resources and ensuring that other operations can continue to run effectively.

In contrast, while the other parameters mentioned serve different purposes, they do not specifically cap memory usage per individual query in the same manner. The total_statement_memory_limit applies to the cumulative memory consumption of all statements executed in a particular session, and the query_memory_limit refers to the memory allocated to a single query but on a higher level setting. Meanwhile, execution_time_limit focuses on the time constraints of query execution rather than memory allocation.