Hi experts,
I experienced a poor performance issue recently. Some queries ran more than 5X slower than before. I checked wait events and I found RESOURCE_SEMEPHORE occupies 35.142% in 6/1. Please see the screenshot 1 below. It is abnormal.
I drilled down wait events info and found it started at 6/1 6:00am. end of part 1 because some forum allows only two images per post.
Row 1:wait type
Row 2:the wait time in milli seconds
Row 3:the wait time as a percentage of the total wait time
Row 4:the average wait time per request