To ensure best system performance while accessing a large number of cases, what approach should be taken?

Utilizing custom indexes is a highly effective approach to enhance system performance when accessing a large number of cases. Custom indexes allow Salesforce to quickly locate records without having to conduct a full scan of the database. This becomes particularly important in scenarios where there is a significant volume of data, as it dramatically reduces the time it takes to retrieve specific records and enhances overall query efficiency.

Indexes are critical in Salesforce because they help optimize search queries, especially when user queries involve standard and custom fields that may not be indexed by default. By implementing custom indexes on fields frequently used in searches or filters, users can experience improved performance when navigating through large datasets, leading to faster loading times and a more responsive system.

While other options, like custom search, record types, and divisions, have their own beneficial uses within the context of case management and data organization, they do not directly improve the underlying performance related to data retrieval as effectively as custom indexes do. Custom search might provide better user experience in finding data but does not inherently speed up the data access process. Record types manage the data's structure, and divisions help in organizing cases across different business units but don’t impact the performance at the database query level as indexes do. Thus, focusing on custom indexes is the most strategic choice