I am storing records in-memory(RAM) and traditional(non SSD) disks. My RAM to disk usage ratio is 1:3. I am not able to understand this large consumption of disk compared to RAM.
My records size is 256 Bytes (it’s actually lesser but 256 is the nearest multiple of 128). I am using default write-block-size (which is 1 MB for non SSD I guess).
I was earlier suspecting that 1MB block size might be holding 1 record only and that could be the reason. But got to know from another thread in forum that a disk block may contain multiple records.
So, what could be the reason of large disk consumption here ?
Also, while doing capacity planning, is there any rule of thumb that disk must be this much times the RAM ?
Kindly suggest. Thanks.