Description:
The MEM QUAN docs say:
"First Seen: The first time the query was seen within the given filter conditions."
http://dev.mysql.com/doc/refman/5.1/en/mem-query-analyzer.html
This suggests that the "First Seen" time is affected by a time interval filter condition, however, that is not true. "First Seen" is the first ever time a "normalized" query was recorded. Here is an example:
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You ran this query in 2010-Aug-15 01:00:00 :
SELECT SLEEP(5);
And then you run this query on 2010-Jan-07 10:00:00:
SELECT SLEEP(123);
Then the normalized query is:
SELECT SLEEP();
The "First Seen" time for this query is always 2010-Aug-15 01:00:00. If you filter by all queries on Jan 07, you will see the normalized "SELECT SLEEP()" query. This happens because indeed this query was slow on Jan 07, but the first time it was seen is still Aug 15.
So in summary, the First Seen is not affected by the filter. It is always the value of the very first time the query was seen.
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How to repeat:
1) in the MEM Dashboard, go to the Query Analyzer tab
2) select a time interval so that you catch a normalized slow query that was "first seen" outside (in the past) of this time interval
3) See that "First Seen" value is previous to the time interval filter condition
Suggested fix:
Document this in all the MEM manuals, making it clear First Seen is not relative to the filter interval condition.
