Row score is a measure of the references used to maintain recently used rows in memory. Each row in memory is assigned a score
based on the number and types of columns they have, which approximates the maximum number of references they could use. Most
columns score as 1; varchar binary, long binary and UUID score as 2; long varchar score as 4.
When the maximum score threshold is reached, the flush size is used to determine how many old rows to remove.
It is recommended that the flush size (measured as a row score) be kept reasonable (less than 1000) to prevent large interuptions.
Row limiting is only enabled when index lazy loading and persistent indexes is turned on.