Tools Tips and Tricks #3: Custom Rowsets using SQL Nexus


This post is part three of the Tools Tips and Tricks series that I started last week. In my T-SQL Tuesday post for this month, I already explained how I always have the inclination of importing data collected into a SQL Server database. I shall touch upon this yet again but this time through the use of SQL Nexus. I am going to use a small script to collect data for the user requests which are executing queries against a particular SQL Server instance. The script that I used to collect data is shown below:


set nocount on
go

while (1=1)
begin

print '-- RequestsRowset'

select GETDATE() as runtime,a.session_id as session_id,
a.start_time as start_time,
a.[status] as [status],
a.command as command,
a.database_id as database_id,
b.objectid
from sys.dm_exec_requests a
cross apply sys.dm_exec_sql_text(sql_handle) b
where session_id <> @@spid

raiserror ('', 0, 1) with nowait

waitfor delay '00:00:05'
end

I have stored the output captured by the above query in a file called CustomRowset.OUT. Using the Edit Custom Rowset option in the SQL Nexus UI (available in the third expandable tab named Data, on the left hand side), I can pull up a UI where I can specify the table name into which the data needs to be imported into (tbl_RequestsExample in this case) and the identifier for the data which needs to be imported (— RequestsRowset in this case). I was executing a WAITFOR DELAY command from another session while the above script was capturing data. I then import the data into a SQL Nexus database using the Importoption. Once this is done, I can then query the database and look into the results which were imported into the database. (see screenshot below). You can extend this functionality to any degree you want and even combine multiple T-SQL commands to capture different result sets in the same loop. You just need to make sure that the rowset identifier for each query result set is unique.

Additionally, if you attempt to capture outputs which have columns with data type length greater than 8000, then the import will fail with the following error in the SQL Nexus log file:

SQLNexus Information: 0 : RowsetImportEngine Error: An unexpected error has occurred:

System.Data.SqlClient.SqlException: The size (8192) given to the column ‘query_text’ exceeds the maximum allowed for any data type (8000).

SQL Nexus 3.0 doesn’t give you the option to add your own column data types using the UI.  Using the form (shown on the left) will treat all columns as varchar. If you want to change this behavior, then modify C:\Users\<user name>\AppData\Roaming\sqlnexus\TextRowsetsCustom.xml directly to add or modify the data types that you want.

Where is this helpful?
Let’s say I decided to collect the output of customized T-SQL script for an extended period of time. Instead of scouring the .txt or .out file manually using a text editor, I can import the data into a table and then run queries on them to save yourself a hair-raising experience and valuable time!

How do I make sure that the data is imported correctly?
1. If you have data which is larger than varchar(8000) in the result sets collected, then make sure to modify the TextRowsetsCustom.xml before you import the data.
2. Give each rowset that you collect an unique identifier. You don’t want the importer to mix-n-match the data you are importing.
3. Add a runtime column using GETDATE() or a variable for scripts capturing data in a loop to ensure that you can track the trend easily without having to second-guess.
4. All columns that are collected in the result set(s) have to be named.
5. Avoid CR/LFs in the result set i.e. don’t use CHAR(13) in your T-SQL script while capturing the data as this seriously confuses the importer as it treats CR/LFs as end-of-row indicator.
6. Either capture the data directly into a file by running the data collection script from Management Studio or use sqlcmd -W parameter if you are capturing the data using sqlcmd. -W ensures that trailing spaces from the result sets are removed.

That is all I have for today. Happy customizing and importing!

Advertisements

It is always good to hear from you! :)

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s