sql library miss rate (2 Merged) oracle database 10.2.0.4 I tried to use a mysql tuning-primer.sh to evaluate my server. and the result for key_buffer is KEY BUFFER Current MyISAM index space = 181 M Current key_buffer_size = 128 M Key cache miss rate is 1 : 12507 Key buffer free ratio = 73 % Your key_buffer_size seems to be too high. How to calculate cache miss rate ? Is there any open-souce software which is able to calculate the cache miss rate of some archs like arm, mips, not only on x86 ? Gary Walker and Lloyd Work review InterSystems' Cache Database. Advertiser Disclosure. Java; A Quick Look at InterSystems' Cache Database. is often a forced tradeoff for the ability to use the grafted technology and you are usually relegated to a second-rate implementation of the grafted cache misses, and miss rate are same. How much faster the machine be with the faster clock? Since the clock rate is doubled, new miss penalty will be 2x40=80 clock cycles. Total memory stall cycles = (0.02 x 80) + 0.36 x (0.04 x 80) = 2.75. CPI. The cache miss rate can be calculated as Key_reads/Key_read_requests. MySQL doesn't have good instrumentation for scientifically choosing a key_buffer_size setting, but there are many unscientific approaches that are better than ratio-based tuning. Cache miss Data not found in cache. Processor loads data from M and copies into cache. This results in extra delay, called miss penalty. Hit time + Miss rate x Miss penalty Assume that Hit time = 5 ns Miss rate = 10% Miss penalty = 100 ns. - Miss Rate DM cache size N == - Miss Rate 2-way associative cache size N/2 Beware: Execution time is only final measure! - Will Clock Cycle time increase? 3. Reducing Misses via Victim Cache How to get fast hit time of Direct Mapped yet still avoid PHP Reporting with Google Charts. Ivan Dabic. August 13, 2014. used php library to make it more interesting and for show-and-tell I have included only summary reports with hourly hit/miss rate and overall hi