Bringing It All Together with SQL Nexus - SQL Server 2012 Internals and Troubleshooting - page 331

want to keep the results of previous imports, then you
need to take a database backup before the next import,
or you can create a new database for each import. This
can be done using the drop-down box for the database,
available in the top right-hand corner of the SQL Nexus
UI window. If you select the New Database option, the
dialog shown in Figure 12-5 appears, into which the diag-
nostic data can be loaded. If you try to import diagnostic
data into a database that has prior SQL Nexus data,
then you will be prompted each time to overwrite the database. You then have two options: Either
overwrite the database and lose the existing imported data in the database, or choose not to overwrite
and create a new database to import the data.

FIGURE 12-5

NOTE Creating a new database to import diagnostic data is a good practice, as it
helps with comparative analysis through T-SQL queries or Reporter.exe , which
is shipped with RML Utilities. You will i nd that the later sections of this chapter
discuss the usage of this tool in detail.

If you face an issue with SQL Nexus while importing the data, there are two places to look depend-
ing on the type of error that you encountered. If you face an issue with the Rowset Importer, which is
responsible for importing the text i les; or with relog.exe, which is responsible for the PerfMon data
import, then you can click the Open Nexus Log option under Tasks (see Figure 12-6) to view the SQL
Nexus log i le. The SQL Nexus log i le is located in your temp folder, which can be accessed using the
%temp% environment variable from the Run prompt.

If you run into an issue while importing the SQL Trace i les, then click the
Open ReadTrace Log option (as shown in Figure 12-6), which is located in
the %temp%/RML folder of your machine. This i le is not only useful for
troubleshooting import issues, but also helps you determine the parameters
passed to the ReadTrace executable in case you want to run the import
manually for different sets of trace i les.

FIGURE 12-6

Analyzing the Aggregated Data
Now that you have loaded the diagnostic data successfully
into a SQL Nexus database, this section describes how you
can leverage the existing set of reports available in SQL
Nexus. The welcome screen of SQL Nexus has a Reports
pane on the left from which you can pick the reports you
want to view. If the report doesn't contain the set of data
necessary to render it, then the pop-up shown in
Figure 12-7 will appear.

FIGURE 12-7