var sidebar_align = 'right';
var content_container_margin = parseInt('290px');
var sidebar_width = parseInt('270px');
Unanswered: Bufferpool physical read greater than logical reads ?
I have this formula to calculate bufferpool hit ratio:
DEC((1 - (FLOAT(TOTAL_DATA_PHYSICAL_READS) / FLOAT(TOTAL_DATA_LOGICAL_READS))) * 100,5,2)
Hypothetical question: is it possible, physical_reads could be greater than logical read resulting into negative hit ratio ?
Recently, I came across one database having Hit Ratio over 115 %.
I wonder, do we need it to tune down ??
You may want to look at the unread prefetch pages metric. It may indicate that prefetching is too aggressive and you are reading more data from disk than you actually need, wasting I/O bandwidth.
That makes sense !!