SK0-004 · Question #828
An administrator is sizing a new server that will run a 1TB database. One of the processor options is the size of the L2 cache. The administrator picks the processor with the least amount of L2…
The correct answer is B. The database will be slower because of a lower amount of cache hits. Processor L2 cache holds frequently accessed data close to the CPU to reduce main memory latency - a smaller L2 cache means more cache misses and slower data retrieval. For a database workload, this directly reduces performance.
Question
An administrator is sizing a new server that will run a 1TB database. One of the processor options is the size of the L2 cache. The administrator picks the processor with the least amount of L2 cache. Which of the following is an outcome of this selection?
Options
- AThe processor will be faster with a lower L2 cache, speeding up database access times.
- BThe database will be slower because of a lower amount of cache hits.
- CDatabase access does not rely on cache, so there will be no difference in performance.
- DThe cost of the processor will be higher.
How the community answered
(22 responses)- A5% (1)
- B86% (19)
- C9% (2)
Why each option
Processor L2 cache holds frequently accessed data close to the CPU to reduce main memory latency - a smaller L2 cache means more cache misses and slower data retrieval. For a database workload, this directly reduces performance.
Less cache does not make a processor faster - cache exists specifically to reduce memory access latency, so reducing it causes more slow main-memory fetches, not fewer.
A smaller L2 cache reduces the amount of hot data - such as index pages and frequently queried rows - that can be stored near the processor, forcing more accesses to slower main memory. Databases repeatedly access the same data structures, so cache hit rate is a key driver of query throughput and latency.
Databases are heavily cache-dependent because they repeatedly read the same index and buffer pool pages - cache hit rate is one of the most critical database performance metrics.
Processors with less L2 cache are typically less expensive to manufacture since cache silicon is costly, not more expensive.
Concept tested: Impact of L2 cache size on database performance
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