CODEWITHSUNDEEP
sql-serverperformanceazure
user334911
user334911

Reputation:

Azure query performance precise meanings

Azure provides query performance, but I need precise meanings for the numbers it gives and I am not aware of a precise definition being given for each of them.

The statistics are Run Count CPU ms/sec Duration ms/sec Physical Reads/sec Logical Writes/sec Logical Reads/sec

Can anyone point me to precise meanings of each of these? E.g. if the same query was run twice in parallel simultaneously and one completes in time A and one in a longer time B, and then the query isn't called at all for some period C (C starts after B ends), how are these each calculated? For instance, does the "per second" at the bottom of each include seconds when the query wasn't running? Is it really "per call" as well? In fact, what time period does "Run Count" get calculated over? A precise meaning to each of these would help me determine what is OK, and what is terribly bad.

Its not even clear where the list of queries under "Query Performance" comes from, i.e. is it the query cache? If so, why does it change so much when I hit refresh?

Upvotes: 1

Views: 210

Answers (1)

flytzen
flytzen

Reputation: 7438

This isn't really a direct answer to your question, but... I have spoken to some of the SQL Azure guys at Microsoft and they seem to not really know either. However, my understanding is that there is no real period for these stats, it's just since the query was first run, I believe, which is hardly helpful. The stats are gathered by running queries on the database, hence why it changes every time you refresh ; the queries to gather the stats are reflected in your results.

There is however a tool available http://social.technet.microsoft.com/wiki/contents/articles/17987.cloud-service-fundamentals.aspx that will give you much better information. I have written about our experiences with this tool here : http://blog.lytzen.name/2013/10/hitting-limits-in-sql-azure.html

Upvotes: 1

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