SQL Server 2005 Performance Dashboard Reports - Professional SQL Server 2005 Performance Tuning - page 487

Overhead
Since these reports are intended to troubleshoot performance problems, they were carefully designed to
minimize the potential impact on your system. The Performance Dashboard Reports do not store data
over time, they do not require reporting services, they do not create a new database, and there will be
absolutely no overhead when you are not interacting with them. By having an interactive drill-through
experience, data can be loaded gradually. This means that a small amount of high-level information
can be retrieved with the dashboard report. Then, based on what you see, you can click a link to see
more information about requests or a graph to inspect locks. This will load a new report targeted to that
specific scenario, consequently minimizing the footprint by only loading the data you are potentially
interested in.
MSDB
The Performance Dashboard Reports setup.sql file creates functions and stored procedures in MSDB.
These objects are commonly used by the reports. If you want to learn how the DMVs are used by the
Performance Dashboard Reports, browse through the setup.sql source or browse the objects in MSDB
after installation.
ManagementData
Almost all information is obtained through the DMVs and catalog views. There is also one report that
allows you to drill into active traces. Even though many Windows administrators are familiar with
performance counters, performance counters are not used for these reports. Since the Performance
Dashboard Reports rely solely on SQL Server technologies and do not capture information over time,
they do not leverage any system performance counters.
ReportingServices
When you diagnose a performance problem, you want to minimize the set of moving parts. So while the
Performance Dashboard Reports use standard SQL Server Reporting Services technology, they do not
require a SQL Server 2005 Reporting Services server. They use client-side Reporting Services technology.
Management Studio parses the T-SQL queries out of the RDL files, gathers the data from the instance,
and passes it to the ReportViewer control to render the report.
You can launch multiple reports or multiple instances of the same report on separate tabs. This is a quick
way to compare information across servers or to compare information on the same server over time. If
you want to save this information, you can export the reports to Excel or PDF.
Security
The Performance Dashboard Reports are executed like any other custom report. Custom reports are run
in the same security context as your connection to Object Explorer. This means that if you are connected
as a sysadmin, all of the report queries will be executed in that context. This is fine if you trust the reports
you are running. If you download a report from the Internet and run it as a system administrator, be
aware that that report can run not only SELECT, but also INSERT, UPDATE, and DELETE statements.
If you do not connect as sysadmin and want to connect as a low-privileged user, you will be able to run
the Performance Dashboard Reports, but you will not see any useful or sensitive data. To view data
from the DMVs, you will need VIEW_SERVER_STATE and VIEW_DATABASE_STATE privileges.