Because
SQL Server Profiler can trace numerous events, it is easy to get lost
when reading the trace output. You need to roughly determine the
information you require and how you want the information grouped. For
example, if you want to see the SQL statements that each user is
submitting through an application, you could trace incoming SQL
statements and group them by user and by application.
When you have an idea about
what you want to trace, you should launch the SQL Server Profiler by
selecting Start, then SQL Server 2008, then Performance Tools, and
finally SQL Server Profiler. You also can launch it from within SSMS
from the Tools menu. When you launch the Profiler, you are presented
with an application window that is basically empty. To start a new
trace, you select the File menu and choose New Trace. In the connection
dialog that is displayed, you can enter the connectivity information for
the server you want to trace. After the connection is established, the
General tab of the Trace Properties window (see Figure 1) is displayed.
The
first place you should look when creating a new trace is at the trace
templates. These templates contain predefined trace settings that
address some common auditing needs. They have preset events, data
columns, and filters targeted at specific profiling scenarios. The
available trace templates, found in the template drop-down on the
General tab of the Trace Properties window, are listed in Table 1.
Table 1. SQL Profiler Templates
Template | Description |
---|
SP_Counts | Tracks all the stored procedures as they start. No event except for the stored procedure starting is traced. |
Standard | Traces the completion of SQL statements and Remote Procedure Calls (RPCs) as well as key connection information. |
TSQL | Traces
the start of SQL statements and RPCs. This template is useful for
debugging client applications where some of the statements are not
completing successfully. |
TSQL_Duration | Traces the total execution time for each completed SQL statement or RPC. |
TSQL_Grouped | Traces the start of SQL statements and RPCs, grouped by Application, NTUser, LoginName, and ClientProcessId. |
TSQL_Locks | Traces
the completion of SQL statements along with the key lock information
that can be used to troubleshoot lock timeouts, deadlocks, and lock
escalation issues. |
TSQL_Replay | Captures
profiling information that is useful for replay. This template contains
the same type of information as the standard template, but it adds more
detail, including cursor and RPC output details. |
TSQL_SPs | Traces
stored procedures in detail, including the start and completion of each
stored procedure. The SQL statements within each procedure are traced
as well. |
Tuning | Performs
a streamlined trace that tracks only the completion of SQL statements
and RPCs. The completion events provide duration details that can be
useful for performance tuning. |
Keep
in mind that the templates that come with SQL Server 2008 are not
actual traces. They simply provide a foundation for you in creating your
own traces. After you select a template, you can modify the trace
setting and customize it for your own needs. You can then save the
modified template as its own template file that will appear in the
template drop-down list for future trace creation.
Trace Name is another property you can modify on the General tab. Trace Name
is a relatively unimportant trace property for future traces. When you
create a new trace, you can specify a name for the trace; however, this
trace name will not be used again. For instance, if you have a trace
definition you like, you can save the trace definition as a template
file. If you want to run the trace again in the future, you can create a
new trace and select the template file that you saved. You will not be
selecting the trace to run based on the trace name you entered
originally. Trace Name is useful only if you are running multiple traces simultaneously and need to distinguish between them more easily.
Tip
Do yourself a favor and
save your favorite trace definitions in your own template. The default
set of templates that come with SQL Server are good, but you will most
likely want to change the position of a column or add an event that you
find yourself using all the time. It is not hard to adjust one of the
default templates to your needs each time, but if you save your own
template with exactly what you need, it makes the task all the more
easy. After you save your own template, you can set it as the default
template, and it will be used by default every time you start the
Profiler.
The Save to File and Save to
Table options on the General tab of the Trace Properties page allow you
to define where the trace output is stored. You can save the output to a
flat file or SQL Server table.
The last option on the
General tab of the Trace Properties window is the Enable Trace Stop Time
option. This scheduling-oriented feature allows you to specify a date
and time at which you want to stop tracing. This capability is handy if
you want to start a trace in the evening before you go home. You can set
the stop time so that the trace will run for a few hours but won’t
affect any nightly processing that might occur later in the evening.
Events
The events and data columns
that will be captured by your Profiler trace are defined on the Events
Selection tab. An example of the Events Selection tab is shown in Figure 2.
The Events Selection
tab consolidates the selection of events, data columns, and filters on
one screen. One of the biggest advantages of the SQL Server 2008 Events
Selection tab is that you can easily determine which data columns will
be populated for each event by looking at the columns that have check
boxes available for the event. For example, the Audit Login event has
check boxes for Text Data, ApplicationName, and others but does not have a check box available for CPU, Reads, Writes,
and other data columns that are not relevant to the event. For those
data columns that have check boxes, you have the option of unchecking
the box so that the data column will not be populated for the event when
the trace is run.
You may find that adding
events in SQL Server 2008 is a bit confusing. When you select a
template, the event categories, selected events in those categories, and
selected columns are displayed in the Events Selection tab. Now, if you
want to add additional events, how do you do it? The answer to this
question lies in the Show All Events check box in the lower-right corner
of the Events Selection tab. When you click this check box, all the
available event categories are listed on the screen. The events and
columns that you had previously selected may or may not be visible on
the screen. They are not lost, but you may need to scroll down the
Events Selection tab to find the event categories that contain the
events you had selected prior to selecting the Show All Events check
box.
You will also notice that all
the events in the categories in which you had events selected are
displayed. In other words, if you had only 2 events selected in the
Security Audit category and then selected the Show All Events check box,
you see all 42 events listed. The only 2 events selected are the ones
you had selected previously, but you need to wade through many events to
see them. One upside to this kind of display is that you can easily
view all the events for a category and the columns that relate to the
events. One possible downside is that the Events Selection tab can be
very busy, and it may take a little extra time to find what you are
looking for.
Tip
If
you capture too many events in one trace, the trace becomes difficult
to review. Instead, you can create several traces, one for each type of
information that you want to examine, and run them simultaneously. You
can also choose to add or remove events after the trace has started.
Keep in mind that you can pause a running trace, change the selected
events, and restart the trace without losing the output that was there
prior to pausing the trace.
Your ability to select and
view events is made easier by using the tree control available on each
event. The tree control allows you to expand or compress an event
category. When you click the + icon next to a category, all the events
are displayed. When you click the – icon, the event category is
collapsed to a single row on the display. When an event has been
selected for use within a category, the category name is shown in bold.
If you want to add all the events in a category to your trace, you can
simply right-click the category name and choose the Select Event
Category option. You can also remove all events in a category by
right-clicking the category name and choosing the Deselect Event
Category option.
Understanding what each of
the events captures can be a challenging task. You can refer to “SQL
Server Event Class Reference” in Books Online for a detailed
description, or you can use the simple Help facility available on the
Events Selection tab. The Events Selection tab has a Help facility that
describes each of the events and categories. The Help text is displayed
on the Events Selection tab below the list of available events. When you
mouse over a particular event or event category, a description of that
item is shown. This puts the information you need at your fingertips.
Note
If you are going to use
SQL Server Profiler, you should spend some time getting to know the
events first and the type of output that Profiler generates. You should
do this first in a development environment or standalone environment
where the Profiler’s effect on performance does not matter. It’s a good
idea to start a trace with a few events at a time and execute some
relevant statements to see what is displayed for each event. You will
soon realize the strength of the SQL Server Profiler and the type of
valuable information it can return.
Data Columns
The columns of information
captured in a Profiler trace are determined by the Data Columns
selected. The Events Selection tab has the functionality you need to add
columns, organize the columns, and apply filters on the data returned
in these columns. As mentioned earlier, you can select and deselect the
available columns for a particular event by using the check boxes
displayed for the listed events. To understand what kind of information a
column is going to return, you can simply mouse over the column, and
Help for that item is displayed in the second Help box below the event
list. Figure 3 shows an example of the Help output. In this particular case, the mouse pointer is over the ApplicationName column returned for the SQL:BatchCompleted event. The first Help box displays information about the SQL:BatchCompleted event, and the second Help box shows information about the data column.
Keep in mind that there is a
default set of columns displayed for each event. You can view additional
columns by selecting the Show All Columns check box. When you choose
this option, an additional set of columns is displayed in the Events
Selection tab. The additional columns are shown with a dark gray
background, and you may need to scroll to the right on the Events
Selection tab to be able to see them. Figure 4 shows an example of the additional columns displayed for the Performance event when the Show All Columns option is used. Some of the additional columns available for selection in this example are BigintData1 and BigintData2.
To organize the columns you
have selected, you can choose the Organize Columns selection on the
Events Selection tab. This Organize Columns window allows you to change
the order of the columns in the trace output as well as group the data
by selected columns. Figure 5 shows an example of the Organize Columns window with the groups and columns selected by default when you use the TSQL_Grouped template.
To change the order of a column,
you simply select the column in the list and use the Up or Down buttons
to move it. The same movement can be done with columns selected for
grouping. You add columns to groups by selecting the column in the data
list and clicking the Up button until the column is moved out of the
Columns list and into the Groups list. For example, in Figure 6.6, you can group the SPID
column by selecting it and clicking the Up button until it moves into
the Groups tree structure instead of the Columns tree structure.
Tip
You can select a particular
column for all events by right-clicking the column header in the Events
Selection tab and choosing the Select Column option. This causes all the
check boxes on the grid to be selected. To remove a column from all
events, you right-click the column header and choose Deselect Column.
The
number of columns selected for grouping and the order of the columns
are both important factors in the way the trace data will be displayed.
If you choose only one column for grouping, the trace window displays
events grouped by the values in the grouped data column and collapses
all events under it. For example, if you group by DatabaseId, the output in the trace window grid displays DatabaseId as the first column, with a + sign next to each DatabaseId
that has received events. The number displayed to the right of the
event in parentheses shows the number of collapsed events that can be
viewed by clicking on the + sign. Figure 6 shows an example of the trace output window that has been grouped by DatabaseId only. The database with a DatabaseId equal to 6
is shown at the bottom of the grid in this example. The grid has been
expanded, and some of the 20 events that were captured for this DatabaseId are shown.
If you select multiple
columns for grouping, the output in the trace window is ordered based on
the columns in the grouping. The events are not rolled up like a single
column, but the trace output grid automatically places the incoming
events in the proper order in the output display.
Tip
The organization of
columns in a trace can happen after a trace has been defined and
executed. If you save the trace to a file or table, you can open it
later and specify whatever ordering or grouping you want to reorganize
the output. This flexibility gives you almost endless possibilities for
analyzing the trace data.
Filters
Filters restrict the event data
returned in your trace output. You can filter the events captured by
the SQL Profiler via the Column Filters button on the Events Selection
tab. An example of the Edit Filter window is shown in Figure 7.
All the available columns for the trace are shown on the left side of
the Edit Filter window. Those columns that have filters on them have a
filter icon displayed next to the column in the column list.
The filtering options in SQL
Server 2008 are similar to those available in SQL Server 2005. Which
options are available depends on the type of column you are filtering
on. The different filtering options are as follows:
Like/Not Like—
This option enables you to include or exclude events based on a
wildcard. You should use the % character as your wildcard character.
When you have completed a filter definition you can press Enter to
create an entry space for another filter definition. For example, with
the ApplicationName filter, you can specify Like Microsoft%,
and you get only those events related to applications that match the
wildcard, such as Microsoft SQL Server Management Studio. This filtering
option is available for text data columns and data columns that contain
name information, such as NTUserName and ApplicationName.
Equals/Not Equal To/Greater Than or Equal/Less Than or Equal—
Filters with this option have all four of these conditions available.
For the Equals and Not Equal To conditions, you can specify a single
value or a series of values. For a series of values, you hit enter after
each value is entered and a new entry space is created for you to enter
the next value. For the other conditional types, a single value is
supplied. For example, you can filter on DataBaseID and input numeric values under the Equals To node of the filtering tree. This filtering option is available for numeric data columns such as Duration, IndexId, and ObjectId.
Greater Than/Less Than— This type of filtering option is available only on time-based data columns. This includes StartTime and EndTime filters. These filters expect date formats of the form YYYY-MM-DD or YYYY-MM-DD HH:MM:SS.
Each data column can use one of
these three filtering options. When you click the data column available
for filtering, you see the filtering options for that column displayed
in the right pane of the Edit Filter window. You enter the values on
which you want to filter in
the data entry area on the filter tree. This input area is shown when
you select a specific filtering option. For multiple filter values, you
press the Enter key after you enter each value. This causes a new data
entry area to appear below the value you were on.
Caution
Filters applied to
columns that are not available or selected for an event do not prevent
the event data from being returned. For example, if you place a filter
on the ObjectName column and choose the SQL:StmtStarting event as part of your trace, the event data is not filtered because ObjectName
is not a valid column for that event. This behavior may seem relatively
intuitive, but it is something to consider when you are receiving
output from a trace that you believe should have been filtered out.
Also, be careful when
specifying multiple filter values and consider the Boolean logic applied
to them. When you specify multiple values for the Like filter, the values are evaluated with an OR condition. For example, if you create a filter on ObjectName and have a Like filter with values of A%, B%, and C%, the filter returns object names that start with A or B or C. When you use the Not Like filter, the AND condition is used on multiple values. For example, Not Like filter values for ObjectName of A% and C% result in objects with names that do not start with A and object names that do not start with C.