Bug #72479 Please add a timestamp so we can see at what time P_S statistics originate
Submitted: 29 Apr 2014 9:29 Modified: 2 May 2014 5:07
Reporter: Simon Mudd (OCA) Email Updates:
Status: Verified Impact on me:
None 
Category:MySQL Server: Performance Schema Severity:S4 (Feature request)
Version:5.7 OS:Any
Assigned to: Marc ALFF CPU Architecture:Any
Tags: mysql-sys, performance_statistics

[29 Apr 2014 9:29] Simon Mudd
Description:
performance_schema and mysql-sys provide some very nice statistics.
One thing that is noticeably missing is that you can get some statistics but you can't see "from when" these statistics originate, so the numbers you see have no 'proper meaning'.

I can send you the output of mysql-sys.schema_table_statistics but looking at this data I do not know if the latencies are for the last minute, hour day or year, so the absolute values are meaningless, unless I actually know that.

How to repeat:
I can send you the output of mysql-sys.schema_table_statistics but looking at this data I do not know if the latencies are for the last minute, hour day or year, so the absolute values are meaningless, unless I actually know that.

I can look at the query_analysis information and see I've done 10,000 queries but without knowing the time period that they're done in the information is also not as useful as it should be.

Suggested fix:
Please consider in 5.7 which is not GA yet to record the time the tables are truncated so this information can be used when providing mysql-sys type views and thus the counters and latency numbers can have a reference period which can be used if necessary.

I don't remember if the truncate table count is currently stored for the p_s tables but if not please also record the number of times the statistics are truncated.

If you don't do this a lot of people are going to ask for this and having to wait for 5.8 would be a real shame as that's likely to be 18+ months further in the future.
[2 May 2014 5:07] Erlend Dahl
Thank you for your feature request.