What should you set the GLOBAL_ALLOCATION_LIMIT parameter to in a 1.5 TB SAP HANA scale-out system with four 1TB nodes?

In a scale-out SAP HANA system, the GLOBAL_ALLOCATION_LIMIT parameter defines the maximum amount of memory that can be allocated to the entire system for data processing. This parameter helps to manage memory consumption and ensures that individual nodes do not allocate more memory than the total available across the system, preventing potential out-of-memory errors or performance issues.

In the case of a 1.5 TB SAP HANA scale-out system with four 1 TB nodes, it’s essential to configure GLOBAL_ALLOCATION_LIMIT to a value that reflects the total available memory but also reserves a portion for overhead and other operations.

Setting the GLOBAL_ALLOCATION_LIMIT to 512 GB strikes an appropriate balance. This is because it limits the allocation to a safe margin while providing flexibility for data handling and system operations. Given the total memory of 4 TB in the system, allocating 512 GB allows for plenty of capacity for ongoing operations and query processing, while also ensuring stability and performance.

Additionally, setting the parameter too high could risk exceeding the practical memory limits in a scale-out configuration and lead to performance degradation or resource contention among nodes.

Hence, the choice of 512 GB is particularly well-aligned with the architecture's need to optimize memory usage without jeopardizing the performance of