Which action improves performance when querying ZC_* tables?

Which action improves performance when querying ZC_* tables?

• A. Filter on arbitrary non-indexed columns.
• B. Sort by non-_C columns.
• C. Cache results in memory indefinitely.
• D. Filter or sort on the _C columns.

Answer: (D)

ZC_* tables are designed with _C columns as the optimized access paths. When you filter on a _C column, the system can use an index-like path to quickly locate only the matching rows, reducing I/O and speeding up the query. Sorting on a _C column aligns with how the data is organized or indexed, so the results can be returned in order without an expensive post-processing sort. Filtering or sorting on non-_C columns misses these optimized paths, often requiring full scans or heavy sorting, which slows things down. Caching results indefinitely isn’t a reliable optimization for a single query and can lead to stale data or memory pressure. So using the _C columns for both filtering and sorting provides the clearest performance benefit.

ZC_* tables are designed with _C columns as the optimized access paths. When you filter on a _C column, the system can use an index-like path to quickly locate only the matching rows, reducing I/O and speeding up the query. Sorting on a _C column aligns with how the data is organized or indexed, so the results can be returned in order without an expensive post-processing sort. Filtering or sorting on non-_C columns misses these optimized paths, often requiring full scans or heavy sorting, which slows things down. Caching results indefinitely isn’t a reliable optimization for a single query and can lead to stale data or memory pressure. So using the _C columns for both filtering and sorting provides the clearest performance benefit.