Question

Summary

I am after some advice on the easiest way to analyze simple data using SQL server and .net

Details

Really simple data – just need really simple way to analyze (with my simple brain)

I have a SQL Server table:

• PKID (Int)
• ApplicationName (VarChar)
• MethodName (VarChar)
• TimeInMs (Integer)
• AdditionalInfo (VarChar)
• DateTime (DateTime)

This table records the length of time it took for various methods to run in various applications. This table could potentially have tens of thousands of rows. I would like to easily extract useful info from this (some of it in real time). I am not sure of the best way to go about this. This kind of data I would like is:

Data
– Average length of time for method call
– Top ten slowest method calls
– Top ten fastest method calls

For the periods of:
– last min, hour, day, week, month
– each day for the last 7 days, each week for the last 10 weeks

For the applications:
– All
– Each individually

Answer 1

I think ojblass was refering to the DataTime field you omitted from your question.

The actual timestamp datatype in MS SQL Server is misleading in name. It has nothing to do with dates and times. It is a binary “version number”. It is used mostly to deal with concurrency issues when updating a row in the table but would be useless for any analysis tasks.

I would suggest improving your column names a bit. Calling a column “DateTime” is confusing and could cause you some trouble in writing queries if you aren’t careful.

Anyway… the queries you are looking for range from simple to quite complex if written directly in TSQL.

Here are some examples (I have not syntax checked these, so they are “approximate” at best):

Average time for a specific method

select avg(TimeInMs) as AvgTime from Table 
where ApplicaitonName = @ApplicationName

Average time for a specific method during the last 1 minute

select avg(TimeInMs) as AvgTime from Table 
where ApplicaitonName = @ApplicationName and 
    [DateTime] >= DATEADD(minute, -1, getdate())

You’ll end up wanting to write stored procedures for most of these. Some of the queries you talk about will require some grouping and such too… I recommend you get a book on TSQL if you go this route.

If you are doing this with LINQ to SQL within your applicaiton, it isn’t much different, but in general LINQ is easier to write (debatable of course).

Here are the same two queries using LINQ to SQL in C# (again, I haven’t tested these, so I could be minor syntax mistakes).

var ctx = new MyDataContext();
var q = (from item in ctx.Table
        where item.ApplicationName == "MyApplication"
        select item.TimeInMs).Average();


var ctx = new MyDataContext();
var q = (from item in ctx.Table
        where item.ApplicationName == "MyApplication" &&
              item.DateTime <= DateTime.Now.AddMinutes(-1)
        select new item.TimeInMs).Average();

How you do the analysis depends on what technologies you are using and what you are doing with the results.

Update:
In answer to follow-up question from comments:

I can’t think of a good way to handle it via storing the desired time intervals in another table that doesn’t get massivly difficult (cursors and dynamically constructed TSQL via the Execture command).

A simpler query that gets the results you want might look like this in TSQL (I’m not advocating that this is the “best” way, but it works and is pretty fast).

select avg(TimeInMs) as AvgTime, 'Last 1 minute' as TimePeriod from Table 
where ApplicaitonName = @ApplicationName and 
    [DateTime] >= DATEADD(minute, -1, getdate())
union
select avg(TimeInMs) as AvgTime, 'Last 2 minutes' as TimePeriod from Table 
where ApplicaitonName = @ApplicationName and 
    [DateTime] >= DATEADD(minute, -2, getdate())
-- //repeat union as many times as needed for each time period